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If a 350 / 4 bolt main engine is bore over 040 ...


Kane

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I have a 1970 Monte Carlo I recently bought It has a late 69 Corvette 350/4 bolt main with 64cc chamber power pack heads. I'm tearing it down to rebuild it to a mild street/strip engine. As I got down to the block I notice the piston stamp showing 040 So, this block been bore. I'm newbie to high performance stuff. My question is since the block been bore what is the displacement size now for the engine. Thanks in advance guys.

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hahahaha im pretty good at math..I jus did the equation and it would be a 360..actually a 360.4

 

the equation is

bore x bore x stroke x .7853982 x 8(# of cyl's)

 

COOL!!!!!!!!!!!!!

its funny cuz a 350 is actually a 349.84 ..... lol

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Max overbore on a small block 350 is .060. on later blocks even that is marginal. bow tie small blocks with siamesed cylinders can go 4.155 You say that you have power pack heads, that was a hot head in the early sixties for 283s not so hot anymore

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69 Corvette 350/4 bolt main with 64cc chamber power pack heads.

Iron small block Chevy heads are extremely durable, but even these pieces will crack. There are later-model, lighter-weight castings that are decent. Most hot rodders do everything on a budget, I know I do & have done so. Few of us have the resources to buy a new block or heads every time we build an engine. So we start with the older stuff that's either well used or that others have tried. More often the history of said castings is documented in numbers, but never a history of running time if you will.. IMO "If you're planning on machining (building) a used block or heads.. make sure the very first thing you do is check for cracks". Usually 25% of blocks received for machining are normally cracked!! Those are pretty high numbers. Starting in the lifter valley where they're are really prone, I guess my point make sure your castings are fine before jumping the gun..ask me how I know. The more machining the weaker the casting! wink

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Been there done that I did up a set of 416 305 heads screw in studs 1.94/1.60 valves new valves tons of time in porting and in the end there was a crack in the chamber but luckly for me I did all the work on the books at work for my self still sucked in the end all ways check for CRACKS

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