.040 overbore on a 351 block ok?

BlackVert

15 Year Member
Oct 3, 2003
5,589
9
98
Bethesda, MD
my engine rebuilding books say that on a healthy 351 block that .060 over is as far as you want to go.

personally i'd rather go only .030 over max, but there is a guy near me selling a 1971 block and a chp 408 kit with .040 over pistons and the price is good.

i'm thinking it'd be fine, just wanted some other opinions.
 
i have a 69 block sitting on the stand punched .040 over! nothing wrong with it at all! And since yours is a early model block also, it has thicker main webbing so the block is all around stronger than a late model
 
Low-5.0 said:
Mine is also .040 over. I don't see it causing a problem, but I don't know if I'd want to go .060 over if you ever need to rebuild it.
dude, you're making 449 at the wheels? screw this 325hp out of a 331 crap ... you're my hero!

he's asking $1350 for the block and the chp 408 kit sans bearings and rings. it is getting harder to pass it up seeing that there is also no shipping on it (it is local).

this kit is .040 over. that would put me at 410 ci. how did you get 418?

what's involved in using a hydraulic roller in it? just retro lifters? it is a 1971 block.
 
BlackVert said:
dude, you're making 449 at the wheels? screw this 325hp out of a 331 crap ... you're my hero!


Theres a dude on corral making 466rwhp with a n/a california pump gas 347. Peaks low too :) Just an fyi.

The 408 sounds good if its all legit and machined right. You need the $400 link bar lifters to make it roller.
 
BlackVert said:
dude, you're making 449 at the wheels? screw this 325hp out of a 331 crap ... you're my hero!

he's asking $1350 for the block and the chp 408 kit sans bearings and rings. it is getting harder to pass it up seeing that there is also no shipping on it (it is local).

this kit is .040 over. that would put me at 410 ci. how did you get 418?

what's involved in using a hydraulic roller in it? just retro lifters? it is a 1971 block.

Mine has the CHP 418 kit in it with .040 over pistons for 420ci. Bearings and rings are cheap, I say go for it! Retro lifters are the way to go. They're a little over $400, but they're worth it.