What is the maximum size that you can bore a mid to late 70's 351w block out too?????? is it .60 over, .40 over, .30 over?

Thanks Tom

 

You should be able to go 60 over just fine.

 

but people tell me about my 302 bored .060 getting hotter than normal
i just put a big radiator on it and i am doing fine

 

I wouldn't go more than 40 over, 60 over will run hot.

 

Thats not necessarily the case every time, I have known a few 351w's that were 60 over and they never had an overheat problem. However i'm not saying it would'nt happen. As for a 302 thats different i would'nt go no more than 40 over.

 

Thanks, I'm not too sure on how bad the block is yet....... this is to replace the 88 351 block, that happens to have a hole in the #2 cylinder water jacket from the wrist pin......

 

the jerks at my local engine shop keep telling me i don't want to bore over .02 over. their reasoning is that when i go to rebuild the engine it leaves more room to bore again. i keep telling them "I DON'T CARE ABOUT REBUILDABILITY!". what a bunch of jerks.

 

get the block sonic tested if in doubt , but 60 over seems a lot for longevity the walls get very thin and flex a lot which can lead to pistons in the water jacket always go with the least amount of overbore that will clean up the cylinders