[donniekak]

The Kia 3.5L DOHC and 3.8L 6G75 with 3/S DOHC heads seem to have the same challenges for mounting - overall not that bad

Odd ball oil pump with OFH what becomes Rear of engine to us, causing it to be in way of intermediate shaft - no 3/S oil pump will work from what I could tell.

I just made a block off plate out of 3/8" thick aluminum, and used the two oil ports on the back with the threaded plugs in them to feed my Remote Oil Filter housing via -10AN fittings and Lines. I believe they are BSP/BTSP/BSPTSPSTPS thread but I don't remember exactly what size.

Oil Pan required mild modification to work with 3/S Trans.
*Drain and Dip stick on rear of engine. Dipstick provision is in oilpan itself not block
*No Starter notch, I took some aluminum tubing, cut a section out, sliced the tubing and welded it into the pan - I also had to grind some material away from the girdle - a AWD TT Trans might not need this since the starter sits out further from the engine slightly with the bigger diameter flywheel
*Hack off the brace type thing on the transmission side and use shorter bolts for the pan.
*Much like the JDM 6G74, you'll need to notch the oil pan for the T-Case which means grinding the crap out of the Girdle there too.

a 4 Bolt TT Pan will NOT work, I tried.

I was able to get by using all 72 brackets, and accessories with light to mild modification. Power steering, Alternator, Drivers Motor Mount Bracket boat anchor, etc.

Most of which consisted of Grind away material and or enlarging holes... not the right way but it worked. 3D Scanning the block and heads then having all the parts cut out of aluminum via CNC would be the preferred way to do it given the resources.

the Bosses for the Front and Rear Motor mounts were there, but most were not drilled/threaded the right size or at all.... However making some custom front and rear motor mounts was actually pretty easy coming from someone who is a terrible fabricator... later on in the project I ended up using the IMR Motorplate, which made mounting the engine fairly easy...


The rest is basically the same as the JDM 6G74 Swap guide,

Exactly, most people with these cars are terrified to make a catch can bracket. But for folks with a welder and some basic fab tools, brackets and mounts aren’t a big deal at all.

 

[RealMcCoy]

I know this is foreign in 3s land, but how hard is it to make a few brackets?

Nobody is saying it can't be done, or crying about it being too hard... You can swap anything in with a little determination and fab skills.

I was simply gauging the different options out there, and how far each was to being a bolt in swap. The Debonair is the ideal choice, the FWD Kia is doable, the Montero SR is probably the worst...

 

[Rokkijumala]

I guess I'm posting to the wrong area but there seems to be wise people talking about these.

I got an offer about 3pcs of complete Pajero 3.5GDI engines. I think euro spec, don't know for sure. All 3 engines for less than 1000 dollars. Not too bad.

I have rebuild my 6g72 engine few times, and I am somehow handy with this kind of things. So experts, please tell me, should I build few 6g74 engines to be some day swapped to my VR-4 TT GTO? I would love to have extra displacement as I could use wide scale of turbos optimized for 1.8 engines. My current build is I think somewhere in 450whp range at the moment, but would it be nice to have a bit more.

Welding new brackets and doing modifications to the oil pan should not be a problem. And I could maybe try something new, and just try to 3D print many parts that don't fit from 6G72, like lower part of intake manifold and coolant housing from the timing belt side. A lot of new cars come with plastic parts in their intake air system and water piping, so I see that it could work.

But what do you say, is it just stupid to go that way? This far I am just valuating my ideas, so feel free to say it is all stupid.

 

[RealMcCoy]

I guess I'm posting to the wrong area but there seems to be wise people talking about these.

I got an offer about 3pcs of complete Pajero 3.5GDI engines. I think euro spec, don't know for sure. All 3 engines for less than 1000 dollars. Not too bad.

I have rebuild my 6g72 engine few times, and I am somehow handy with this kind of things. So experts, please tell me, should I build few 6g74 engines to be some day swapped to my VR-4 TT GTO? I would love to have extra displacement as I could use wide scale of turbos optimized for 1.8 engines. My current build is I think somewhere in 450whp range at the moment, but would it be nice to have a bit more.

Welding new brackets and doing modifications to the oil pan should not be a problem. And I could maybe try something new, and just try to 3D print many parts that don't fit from 6G72, like lower part of intake manifold and coolant housing from the timing belt side. A lot of new cars come with plastic parts in their intake air system and water piping, so I see that it could work.

But what do you say, is it just stupid to go that way? This far I am just valuating my ideas, so feel free to say it is all stupid.

The direct injected 6G74 is not an engine we ever got in the US, and I have no experience with it. Going from a Pajero/Montero configuration to a 3S will be a ton of work though. It certainly can be done, and has been done, but it's not the easy way to go.

 

[enkaio]

Over in on of the UK forums GTO Nemesis has a nice build thread where the Pajero (Euro - Wrong orientation) was modified to fit. Obviously not using the GDI heads and intake.

I personally can't weld TIG or justify to invest into a proper welder. (Just got MIG /MAG) so water housing was my dead end for the plans - I'm not sure a stainless or regular steel tubing with "remote" Thermostat (inside the hoses) would of have sealed ever due to heat expansion to the block.

As for 3d part printing, the lower intake had on my 6g72 already up to 110°C / 230F probably more. Not sure if the 400°C processing ~ Nylon or PEEK or similar source material suitable enough. ( oil and fuel / E85 Ethanoal resistant over a long timeframe) which would make prototyping favorable from a price point.

 

[Rokkijumala]

Over in on of the UK forums GTO Nemesis has a nice build thread where the Pajero (Euro - Wrong orientation) was modified to fit. Obviously not using the GDI heads and intake.

I personally can't weld TIG or justify to invest into a proper welder. (Just got MIG /MAG) so water housing was my dead end for the plans - I'm not sure a stainless or regular steel tubing with "remote" Thermostat (inside the hoses) would of have sealed ever due to heat expansion to the block.

As for 3d part printing, the lower intake had on my 6g72 already up to 110°C / 230F probably more. Not sure if the 400°C processing ~ Nylon or PEEK or similar source material suitable enough. ( oil and fuel / E85 Ethanoal resistant over a long timeframe) which would make prototyping favorable from a price point.

Nice, i gotta check that build.

I will first check if that engine looks decent as I propably need to drop one out from Pajero and see what is wrong with it.

I think even ABS could be an opinion. At least some cars seem to have a lot parts directly bolted to the engine made of ABS.

 

[stevecooper]

Given that the complete Debonair 3.5 is pretty much impossible to find, depending on what part of the world you're in, the easy way is to use a Pajero 3.5 GDI block, complete engines don't cost much. Also get a complete 3.5 Diamante SOHC. Combined with a GTO/ 3KGT engine you've got pretty much everything you need.
The GDI blocks are the same configuration as the Debonair and same as 2nd gen 3S. Some of them depending on date don't have all the holes drilled and threaded for all the brackets, it might not matter.
The 2nd gen 3s sump can be made to fit quite easily .That gives block and crank. The SOHC, you get crank, rods , dished pistons, front pulley, lower intake manifold, pretty much everything else comes from the GTO / 3k. All the brackets can be made to fit.
About the blocks, the 72, 74 and 75, there's 2 main configurations, the crossover oiling and the non crossover.
They use different sumps, oil pumps , water pumps as well as auto tensioner and cambelt length.
Using the original configuration, it's crossover, oil filter at the front side.
If you use the wrong block the main problem is the driveshaft interfering with the oil filter.
It's extremely time consuming to do but not really difficult.
Most important part is getting the cams dialled in right,
If you start with a Pajero DOHC from 94 ish, they have the 3A heads which have very small intake ports.

This here is the ideal engine to start with.

Mitsubishi Pajero 2009 3.8 litre V6 6G75 timing belt tensioner adjustment precaution warning


It's a pajero
3.8
Look at the oil filter, it's same as GTO configuration meaning it's got the crossover oiling system.
No I don't have one myself yet but it's only a matter of time.

With the right mods you could make the outside look just like original so no one would know it's a 3.8, then with the right internal mods you could punch it out to 4.5?.
Twin turbo of course.

 

[crofoot]

Why put a 6G74 in my N/A?
The increased displacement means plenty more downlow torque. The proper engine to use, from a 1992-1998 Mitsubishi Debonair pumps out an impressive 191 kW or 256 hp according to Wiki (I’ll confirm this myself when I hunt down a debonair brochure!) So not only does the bigger engine produce more torque, but it also produces more power. It’s a win-win situation!
Advantages vs Disadvantages

Advantages of a 6G74 DOHC
To any Jo-blow it’ll look like a stock 3L
More torque
More power
More return for the same mods done vs a 6G72
Plenty of potential to stroke, or turbocharge, with fantastic results.
Parts are NOT hard to come by as some may think. Timing belt is simply a Pajero/Montero 3.5L DOHC belt. Not available in Kevlar though.
Price is similar if not the same as a 6G72

Disadvantages
You MUST ensure the engine you buy is complete. Alternator/power steering brackets, crossover pipe, and water tube from the water pump is a MUST.
You will get the bug for more power and more torque from your engine....it’s a very fun drive!
Lower stock rev limiter on the debonair (6200RPM) means the powerband isn’t as wide.
Taller engine means it might interfere or come close to your front strut brace/tower bar.
Your stock downpipe will bolt up with some 1cm spacers from your local exhaust shop. You’ll need 4 gaskets in total and she’ll bolt right up.
6G74 Specifications

6G72 6G74
Bore: 91.1 93
Stroke: 76 85.8
Crank Offset Radius: 38 42.9
Rod Length: 140 152
Piston Compression Height: 31.75 31.75
Deck Height: 210 228
Main Bearing Diameter: 60 64
Rod Bearing Diameter: 50 55
Compression Ratio: 10:1 10:1
Piston Pin Diameter: 22 ??
ROD Ratio(L/S): 1.84 1.77

Engine Size: cc 2972 3497

Correct vs incorrect engine to buy
You are wanting as a direct bolt in solution an engine from a FWD Mitsubishi Debonair. Ebay ads will list these incorrectly as Montero or Pajero engines. Regardless of what they say, if the engine looks like that out of a 3000GT then that’s the engine for you. However to be sure I would always confirm with the seller it’s 100% a FWD layout engine and is the one for sale in the pictures.
6G72/6G74 head compatibility
I have read many things stating heads are different which we need to clear up!
IF the engine you are using is from a RWD Pajero or Montero, YES the heads are different!
IF the engine you have is the proper JDM Debonair engine, NO The heads are 100% the same!
I have confirmed this with ASA (The Mitsubishi parts program) so there should need to be any more false information floating around the forum anymore.
To put it simply, if you have the FWD model, you are 100% good to go.
Parts interchange-ability with a 6G72
I have been working on my 6G74 for a few years now and I know have a good idea of what fits and what does not.
Here is a list of parts I know of that WILL fit onto your 6G74 weather right away, or if you need spares
Intake (from air cleaner up to TB)
Throttle body
Upper intake manifold (it is actually 3mm longer then a 3L one so technically different but for arguments sake, it’ll work no problems)
Front rocker cover
Front timing cover
Coil pack and PTU
Exhaust manifolds
Alternator
Power steering pump
If your 6G72 is a 93+ with dual serpentine belts, Crank pulley will work
Parts which are different
Lower intake manifold on the 6G74 is wider for the wider V of the block
Rear rocker cover and rear timing belt cover are different. One solution is to use your 3L ones. They are different in that the bolt hole spacing is closer on the rear rocker cover/timing belt cover then they are the 72 ones. I cannot confirm if 1993+ 6G72 rear rocker cover’s and timing belt covers are different/the same as the 1991-1993 models.
Alternator/Power steering bracket
Sump is 2 piece. 6G72 is one piece.
Lower timing cover is taller aswell.
Injectors will fit however DO NOT use 6G72 Injectors.

Modifications to enhance your N/A 6G74
Adding adjustable cam gears and setting them around the normal -3 +1 adjustments will give you alot more mid and top end power. I noticed the power would drop off sharply around 6300RPM before adding them, with them installing it would rev nice and smooth all the way to 7000RPM

A/C Delete. I did this as I cannot really be bothered using my A/C. Deleting it saves close to 20kg in total. I kept the upper pulley. I used a 6PK1035 belt. Fitted perfectly.

272 camshafts. I have recently installed a set of DR 272 reground camshafts w/shims. I haven’t had a good chance to take the car out for a test’n’tune so I cannot comment on these. Let’s just say that you won’t be making LESS power with them that’s for sure!

Common Q’s and A’s
Will it bolt right into my 3000GT/Stealth?
If you own a FWD Model, YES, this engine will 100% bolt right up
Will my fuel system need upgrading?
If you are upgrading from a SOHC 12v 6G72 then YES, your fuel pump will need upgrading.
If you are upgrading from a DOHC 24v 6G72 then NO, it will not need upgrading.
Will it work in a 1993+ car?
Yes, All electronics will plug right up if your car/engine harness has the two separate plugs for the separate crank and cam angle sensors on the timing belt side of the engine
If you have a 1991-early 1993 engine you will need to perform a wiring modification to adapt to the new harness
Will my 3L ECU run right away?
Yes, your 3L ECU will fire it up right away.
Due to the aggressive timing of the 3L it is recommended to only run High octane fuel to prevent any chance of knock. There have been cases of a few 6G74 engines running 6G72 ECU’s failing because of this.
Will my Transmission bolt up?
Yep, no worry’s here. Your manual gearbox will bolt right up, as will your automatic transmission. The bolt pattern is exactly the same.
I have some spare injectors from my 6G72, can I use these?
Technically, they will bolt up and work. However they are a smaller capacity so refrain from using them at all costs. Playing around with fuel injectors without proper fuel control can turn nasty. It’s best to avoid these hassles in the first place.
I have a spare 6G72 Oil pump, can I use it?
Only if it's from a 1993+ onwards car. In fact most of the lower timing belt components will work aswell, timing tensioner, idler pulley, hydraulic tensioner, that swing arm that is being pushed on by the hydraulic tensioner. Even the lower CAS plate and sensor will work.

References;
6G74 3.5L Engine Main Swap details!...JOHN MONNIN'S PERSONAL 3000GT/STEALTH FAQ
Mitsubishi Debonair - Wikipedia, the free encyclopedia

I made this to be a quick stop for people considering this conversion as there is an influx of basic questions always asked. If ANYONE has something to contribute, please PM me and I will modify it and/or add/remove things.

I was thinking about swapping a 6g74 into my fwd 3000gt but after talking to the transmission warehouses near me I was told that the flywheels are different enough that it won’t work. It is the same bolt pattern between the 6g74 and the 6g72 but the weight distribution and the diameter are different. If I were to use the 6g72 flywheel they told me I would snap my crankshaft. If I were to get a 6g74 flywheel the starter would no longer engage correctly. Is there a solution I don’t see or is there just no option for me?

 

[Stealth es 92]

Why put a 6G74 in my N/A?
The increased displacement means plenty more downlow torque. The proper engine to use, from a 1992-1998 Mitsubishi Debonair pumps out an impressive 191 kW or 256 hp according to Wiki (I’ll confirm this myself when I hunt down a debonair brochure!) So not only does the bigger engine produce more torque, but it also produces more power. It’s a win-win situation!
Advantages vs Disadvantages

Advantages of a 6G74 DOHC
To any Jo-blow it’ll look like a stock 3L
More torque
More power
More return for the same mods done vs a 6G72
Plenty of potential to stroke, or turbocharge, with fantastic results.
Parts are NOT hard to come by as some may think. Timing belt is simply a Pajero/Montero 3.5L DOHC belt. Not available in Kevlar though.
Price is similar if not the same as a 6G72

Disadvantages
You MUST ensure the engine you buy is complete. Alternator/power steering brackets, crossover pipe, and water tube from the water pump is a MUST.
You will get the bug for more power and more torque from your engine....it’s a very fun drive!
Lower stock rev limiter on the debonair (6200RPM) means the powerband isn’t as wide.
Taller engine means it might interfere or come close to your front strut brace/tower bar.
Your stock downpipe will bolt up with some 1cm spacers from your local exhaust shop. You’ll need 4 gaskets in total and she’ll bolt right up.
6G74 Specifications

6G72 6G74
Bore: 91.1 93
Stroke: 76 85.8
Crank Offset Radius: 38 42.9
Rod Length: 140 152
Piston Compression Height: 31.75 31.75
Deck Height: 210 228
Main Bearing Diameter: 60 64
Rod Bearing Diameter: 50 55
Compression Ratio: 10:1 10:1
Piston Pin Diameter: 22 ??
ROD Ratio(L/S): 1.84 1.77

Engine Size: cc 2972 3497

Correct vs incorrect engine to buy
You are wanting as a direct bolt in solution an engine from a FWD Mitsubishi Debonair. Ebay ads will list these incorrectly as Montero or Pajero engines. Regardless of what they say, if the engine looks like that out of a 3000GT then that’s the engine for you. However to be sure I would always confirm with the seller it’s 100% a FWD layout engine and is the one for sale in the pictures.
6G72/6G74 head compatibility
I have read many things stating heads are different which we need to clear up!
IF the engine you are using is from a RWD Pajero or Montero, YES the heads are different!
IF the engine you have is the proper JDM Debonair engine, NO The heads are 100% the same!
I have confirmed this with ASA (The Mitsubishi parts program) so there should need to be any more false information floating around the forum anymore.
To put it simply, if you have the FWD model, you are 100% good to go.
Parts interchange-ability with a 6G72
I have been working on my 6G74 for a few years now and I know have a good idea of what fits and what does not.
Here is a list of parts I know of that WILL fit onto your 6G74 weather right away, or if you need spares
Intake (from air cleaner up to TB)
Throttle body
Upper intake manifold (it is actually 3mm longer then a 3L one so technically different but for arguments sake, it’ll work no problems)
Front rocker cover
Front timing cover
Coil pack and PTU
Exhaust manifolds
Alternator
Power steering pump
If your 6G72 is a 93+ with dual serpentine belts, Crank pulley will work
Parts which are different
Lower intake manifold on the 6G74 is wider for the wider V of the block
Rear rocker cover and rear timing belt cover are different. One solution is to use your 3L ones. They are different in that the bolt hole spacing is closer on the rear rocker cover/timing belt cover then they are the 72 ones. I cannot confirm if 1993+ 6G72 rear rocker cover’s and timing belt covers are different/the same as the 1991-1993 models.
Alternator/Power steering bracket
Sump is 2 piece. 6G72 is one piece.
Lower timing cover is taller aswell.
Injectors will fit however DO NOT use 6G72 Injectors.

Modifications to enhance your N/A 6G74
Adding adjustable cam gears and setting them around the normal -3 +1 adjustments will give you alot more mid and top end power. I noticed the power would drop off sharply around 6300RPM before adding them, with them installing it would rev nice and smooth all the way to 7000RPM

A/C Delete. I did this as I cannot really be bothered using my A/C. Deleting it saves close to 20kg in total. I kept the upper pulley. I used a 6PK1035 belt. Fitted perfectly.

272 camshafts. I have recently installed a set of DR 272 reground camshafts w/shims. I haven’t had a good chance to take the car out for a test’n’tune so I cannot comment on these. Let’s just say that you won’t be making LESS power with them that’s for sure!

Common Q’s and A’s
Will it bolt right into my 3000GT/Stealth?
If you own a FWD Model, YES, this engine will 100% bolt right up
Will my fuel system need upgrading?
If you are upgrading from a SOHC 12v 6G72 then YES, your fuel pump will need upgrading.
If you are upgrading from a DOHC 24v 6G72 then NO, it will not need upgrading.
Will it work in a 1993+ car?
Yes, All electronics will plug right up if your car/engine harness has the two separate plugs for the separate crank and cam angle sensors on the timing belt side of the engine
If you have a 1991-early 1993 engine you will need to perform a wiring modification to adapt to the new harness
Will my 3L ECU run right away?
Yes, your 3L ECU will fire it up right away.
Due to the aggressive timing of the 3L it is recommended to only run High octane fuel to prevent any chance of knock. There have been cases of a few 6G74 engines running 6G72 ECU’s failing because of this.
Will my Transmission bolt up?
Yep, no worry’s here. Your manual gearbox will bolt right up, as will your automatic transmission. The bolt pattern is exactly the same.
I have some spare injectors from my 6G72, can I use these?
Technically, they will bolt up and work. However they are a smaller capacity so refrain from using them at all costs. Playing around with fuel injectors without proper fuel control can turn nasty. It’s best to avoid these hassles in the first place.
I have a spare 6G72 Oil pump, can I use it?
Only if it's from a 1993+ onwards car. In fact most of the lower timing belt components will work aswell, timing tensioner, idler pulley, hydraulic tensioner, that swing arm that is being pushed on by the hydraulic tensioner. Even the lower CAS plate and sensor will work.

References;
6G74 3.5L Engine Main Swap details!...JOHN MONNIN'S PERSONAL 3000GT/STEALTH FAQ
Mitsubishi Debonair - Wikipedia, the free encyclopedia

I made this to be a quick stop for people considering this conversion as there is an influx of basic questions always asked. If ANYONE has something to contribute, please PM me and I will modify it and/or add/remove things.

What wiring modification for the 91

 

[Warzone]

What wiring modification for the 91

91-92 Cars have just a Cam Angle Sensor whereas 93+ Cas have both a Cam and Crank Angle Sensor. The Cam Angle Sensor is installed on the front of the engine instead of the back like 91-92 cars also, along with being an entirely different sensor, and plug. So the wiring is different. It can be corrected a few different ways. There is plenty of info on here on the forums including wiring diagrams.

The easiest way IMO is to just simply steal the 91-92 Cam Angle Sensor, and mounting bracket off the back of your 6g72, and install it on the 6G74...Like the 6G72 DOHC's, The slot in the Rear Intake Camshaft for the Cam Angle Sensor should still be there... the hole is just covered by a rubber cover and metal bracket which is easily removed. I've done it this way a few times now when mixing different generations of heads, engines, electronics into X year Chassis.

 

[jose.alonso]

Why put a 6G74 in my N/A?
The increased displacement means plenty more downlow torque. The proper engine to use, from a 1992-1998 Mitsubishi Debonair pumps out an impressive 191 kW or 256 hp according to Wiki (I’ll confirm this myself when I hunt down a debonair brochure!) So not only does the bigger engine produce more torque, but it also produces more power. It’s a win-win situation!
Advantages vs Disadvantages

Advantages of a 6G74 DOHC

• To any Jo-blow it’ll look like a stock 3L
• More torque
• More power
• More return for the same mods done vs a 6G72
• Plenty of potential to stroke, or turbocharge, with fantastic results.
• Parts are NOT hard to come by as some may think. Timing belt is simply a Pajero/Montero 3.5L DOHC belt. Not available in Kevlar though.
• Price is similar if not the same as a 6G72

Disadvantages

• You MUST ensure the engine you buy is complete. Alternator/power steering brackets, crossover pipe, and water tube from the water pump is a MUST.
• You will get the bug for more power and more torque from your engine....it’s a very fun drive!
• Lower stock rev limiter on the debonair (6200RPM) means the powerband isn’t as wide.
• Taller engine means it might interfere or come close to your front strut brace/tower bar.
• Your stock downpipe will bolt up with some 1cm spacers from your local exhaust shop. You’ll need 4 gaskets in total and she’ll bolt right up.

6G74 Specifications

6G72 6G74

• Bore: 91.1 93
• Stroke: 76 85.8
• Crank Offset Radius: 38 42.9
• Rod Length: 140 152
• Piston Compression Height: 31.75 31.75
• Deck Height: 210 228
• Main Bearing Diameter: 60 64
• Rod Bearing Diameter: 50 55
• Compression Ratio: 10:1 10:1
• Piston Pin Diameter: 22 ??
• ROD Ratio(L/S): 1.84 1.77
• 
  
• Engine Size: cc 2972 3497

Correct vs incorrect engine to buy
You are wanting as a direct bolt-in solution an engine from a FWD Mitsubishi Debonair. Ebay ads will list these incorrectly as Montero or Pajero engines. Regardless of what they say, if the engine looks like that out of a 3000GT then that’s the engine for you. However to be sure I would always confirm with the seller it’s 100% a FWD layout engine and is the one for sale in the pictures.
6G72/6G74 head compatibility
I have read many things stating heads are different which we need to clear up!
IF the engine you are using is from a RWD Pajero or Montero, YES the heads are different!
IF the engine you have is the proper JDM Debonair engine, NO The heads are 100% the same!
I have confirmed this with ASA (The Mitsubishi parts program) so there should need to be any more false information floating around the forum anymore.
To put it simply, if you have the FWD model, you are 100% good to go.
Parts interchange-ability with a 6G72
I have been working on my 6G74 for a few years now and I now have a good idea of what fits and what does not.
Here is a list of parts I know of that WILL fit onto your 6G74 weather right away, or if you need spares
Intake (from air cleaner up to TB)
Throttle body
Upper intake manifold (it is actually 3mm longer than a 3L one so technically different but for argument's sake, it’ll work with no problems)

• Front rocker cover
• Front timing cover
• Coil pack and PTU
• Exhaust manifolds
• Alternator
• Power steering pump

If your 6G72 is a 93+ with dual serpentine belts, the Crank pulley will work
Parts which are different

• Lower intake manifold on the 6G74 is wider for the wider V of the block
• Rear rocker cover and rear timing belt cover are different. One solution is to use your 3L ones. They are different in that the bolt hole spacing is closer on the rear rocker cover/timing belt cover than they are the 72 ones. I cannot confirm if 1993+ 6G72 rear rocker cover’s and timing belt covers are different/the same as the 1991-1993 models.
• Alternator/Power steering bracket
• Sump is 2 piece. 6G72 is one piece.
• Lower timing cover is taller aswell.
• Injectors will fit however DO NOT use 6G72 Injectors.

Modifications to enhance your N/A 6G74
Adding adjustable cam gears and setting them around the normal -3 +1 adjustments will give you a lot more mid and top-end power. I noticed the power would drop off sharply around 6300RPM before adding them, with them installed it would rev nice and smooth all the way to 7000RPM

A/C Delete. I did this as I cannot really be bothered using my A/C. Deleting it saves close to 20kg in total. I kept the upper pulley. I used a 6PK1035 belt. Fitted perfectly.

272 camshafts. I have recently installed a set of DR 272 reground camshafts w/shims. I haven’t had a good chance to take the car out for a test’n’tune so I cannot comment on these. Let’s just say that you won’t be making LESS power with them that’s for sure!

Common Q’s and A’s
Will it bolt right into my 3000GT/Stealth?
If you own a FWD Model, YES, this engine will 100% bolt right up
Will my fuel system need upgrading?
If you are upgrading from a SOHC 12v 6G72 then YES, your fuel pump will need upgrading.
If you are upgrading from a DOHC 24v 6G72 then NO, it will not need upgrading.
Will it work in a 1993+ car?
Yes, All electronics will plug right up if your car/engine harness has the two separate plugs for the separate crank and cam angle sensors on the timing belt side of the engine
If you have a 1991-early 1993 engine you will need to perform a wiring modification to adapt to the new harness
Will my 3L ECU run right away?
Yes, your 3L ECU will fire it up right away.
Due to the aggressive timing of the 3L it is recommended to only run High octane fuel to prevent any chance of knock. There have been cases of a few 6G74 engines running 6G72 ECU’s failing because of this.
Will my Transmission bolt up?
Yep, no worry’s here. Your manual gearbox will bolt right up, as will your automatic transmission. The bolt pattern is exactly the same.
I have some spare injectors from my 6G72, can I use these?
Technically, they will bolt up and work. However they are a smaller capacity so refrain from using them at all costs. Playing around with fuel injectors without proper fuel control can turn nasty. It’s best to avoid these hassles in the first place.
I have a spare 6G72 Oil pump, can I use it?
Only if it's from a 1993+ onwards car. In fact most of the lower timing belt components will work aswell, timing tensioner, idler pulley, hydraulic tensioner, that swing arm that is being pushed on by the hydraulic tensioner. Even the lower CAS plate and sensor will work.

References;
6G74 3.5L Engine Main Swap details!...JOHN MONNIN'S PERSONAL 3000GT/STEALTH FAQ
Mitsubishi Debonair - Wikipedia, the free encyclopedia

I made this to be a quick stop for people considering this conversion as there is an influx of basic questions always asked. If ANYONE has something to contribute, please PM me and I will modify it and/or add/remove things.

it's a good thing this site keeps all these old messages still posted...