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3KGT Holy Grail

50K views 166 replies 30 participants last post by  MichaelMR2 
#1 · (Edited)
Found a 3.8l 6G75 Block (4.0l + potential) specifically to fit the 3000GT / Stealth chassis





Found in these.. V77W Pajero



and you'll need one these.. JDM 6G74 DOHC (use everything off this but the block)



P.S- For the ppl who dont know the 6g74/75 block have the same deck height so you'll need most of the gear of this engine to make up added deck height, the 72 dohc gear doesn't fit - check Wrench Monkeys page to get a better understanding of what i mean --- http://wrenchmonkey.com/Webpages/6G74swap.html

and to top it off one of these..

NBF 6g74 4.1L short block - Welcome to the New Racing Generation Forums .

and hey Presto !!!!!!!!
 
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#99 ·
I was wondering if you'd crop up or not :p

I recon 99% of people are better off just boring out the 74 block though...looks like the 75 will be only an extra mm in there(while it looks good, it has a backwards step in the water channel side of the bore) and going to all the hassle of getting extra Bosses put on the block won't be worth it for that extra .05L of capacity :(

I put 3K into buying this block so it's going to work one way or another :p
 
#110 ·
It clearly says 6G75 S4 on the side...... what's not to believe?
 
#112 ·
Well if you can enhance that picture or get a better one the tab under the last header should have the engine number on it.

Also a quick google search of 6G75 S4 tells me it was used in the Mitsu Endeavor.
 
#118 ·
"well, I measured the bores and wall thicknesses and all that rubbish

here we go

6g75

water passages (widest part) 10mm
edge of bore to inside of block 21mm
edge of block to inside edge of block (thinnest)138mm
water passage to bore ~8mm
water passage to edge of inside of block ~8mm

6g74

water passages (widest part) 12mm
edge of bore to inside of block 23mm
edge of block to inside edge of block (thinnest) 138mm
water passage to bore ~8mm
water passage to edge of inside of block ~8mm

keep in mind none of this is sonic...that will have to be in a few weeks or something (probably a month) pics showing my measurements are in the usual spot "


being lighter, does this mean that it's basically a bored 74 with different bosses? what i'm really hanging on is the cylinder wall thickness, and the water jacket "step" in the 75 is'nt going to help in this department.

stroked and bored to the max, would it be possible that both blocks would end up the same displacement, due to the 75 having thinner cylinder walls already? or would the 75 still end up with slightly more displacement?
 
#120 ·
lol i hear ya, i just had to finish reading everyone elses posts on the matter, and did'nt want to loose where yours was, so i just copied and pasted instead of quoting. i did add quotation marks, they're just small. lol

anyway, mad props to you for all this research for us. i'm very exited to see your final outcome with this beast.

also excited to see if anyone ever does find a 6g75 with the same bosses as a 74 "possibly the endevor?", but with the external dimentions of both blocks being the same, i'd still see it as little more than a pre-bored 6g74 untill some evidence shows otherwise.

and lastly, i'm exited to see how much better the 3 hole main bearing design of the 75 is compared to normal 72 & 74 bearings, and if it is alot more reliable, could 72-74 style blocks be modified to use this new bearing design?
 
#121 ·
not sure that the bearings are that different, anyone got pics of the 72 bearings (up close/highrez)

I'm taking my blocks into to get checked on FRIDAY...this shall be interesting, I really don't want to stuff around with the 72 block but then gain I don't want to throw away 3k :p
 
#127 ·
GOOD NEWS! :D

called up the block guy, he's just finished checking both the 74 and 75 over.

he said that assuming it's going to take high boost (30+psi) his recommendation is to keep the bore wall over 5.1mm so based on his results:

the 74 block is fine up to 95mm
the 75 block is fine up to 97mm

so the 75 fookaround might actually be worth all this trouble (it has a 1mm larger bore radius).

the bore testing guy is now going to take both blocks to his welding guy (regularly welds stuff on blocks) to have a look and get a quote.. he says it's usually $100 per Boss.
 
#128 ·
Annnd bad news, I cannot weld boss's onto the block, they are saying that most of what I want to weld on are in spots that are too thin...

so I'm going to get all the metal work I'll need, take it down there and see what ones he can weld on, from there it will be a case of seeing what of bdrank's braces will fit (and if so paying him to make me some :|)
 
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