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Is it possible to take my 2.8 and have it bored to 3.4? i saw a place online selling the 2.8to3.4 conversion blocks for a little over a grand, but can i just take my current block and get it bored? it seems like that is what chevy did to make these engines anyway. Am i totally wrong?
 

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No, you can't at least not safely.

GM actually cast a different block for the 3.4 with larger bores and more meat around the bores. Also a longer stroke crank was used.

2.8L bore 3.503" (89mm)
3.4L bore 3.62" (92mm)

2.8L stroke 2.99" (75mm)
3.4L stroke 3.31" (84mm)
 

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You can go to 3.2L mind you - just get a 3.1L crank, then bore it +.030 (just did one a month or so ago for a guy).
 

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Don't have any actual numbers on it - just the ass-o-meter. Both mine and the owners.

It's in an '88 Fiero (automatic). I'd say it's got to be the quickest automatic one I've driven, and the owner is blown away by it.
 

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That'd depend on a few things - compression ratio, induction system, cam, etc.

Also, the 'true' 3.1 would have used the more efficient aluminum heads that you can't use (if you want to keep the S10 intake setup).
 

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i had my 86 project bored to 3.1, but dont go 3.2, at 3.1 the walls are so thin, paper thin
 

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Blaze86lo said:
i had my 86 project bored to 3.1, but dont go 3.2, at 3.1 the walls are so thin, paper thin
Huh? You mean your're still using a 2.8 (76mm stroke) crank, with a 92mm bore?

I really hope you stroked though. I stroked mine with a 3.1 (and .75mm over bore) to a 3.2 and there is still plenty of cylinder wall left.
 

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S-Clusive's Jester
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how much did all that cost? was it worth it?
 
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