thinkin bout swapin my 305 tbi to a 79 350 bore 40 over (357) with a mild cam how much of a difference u think will i tell in HP

 

thinkin bout swapin my 305 tbi to a 79 350 bore 40 over (357) with a mild cam how much of a difference u think will i tell in HP

 

You really haven't given us any information so our guess is as good as yours is. a 357 is bigger than a 305, so you will make more power... but HOW MUCH comes down to what parts are in it.

 

well im pretty sure its a stock 350 bore 40

 

Still doesn't tell me anything. You need to know all of your engine specs before you can get anywhere near an answer.

 

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well flat top pistons, stock heads redone, mild cam, stock 350 bored 40 over

 

Depends on the 350 you put in.

The year the block was cast and the extra .040" of bore are totally irrelevant. What pistons are in it, what machine work was done (in particular, were the decks cut down to match the piston height), what heads are on it, things like that will matter ALOT more.

 

There's just so much more to it. Cam specs, what heads, which pistons, what sort of shape the rings are in, and a few other variables.

 

Will you be topping it with the TBI, stock manifolds, stock exhaust and all emissions equipment? If you don't, you probably wont get it inspected. If you do, you probably wont make more than 225HP.

 

Oh boy, two threads on the same thing.

 

Merged the threads.

Stock '79 350 heads are so horrible, most likely you won't make any more power with the 350 than you have now with the 305. If you doubt that, consider that both were rated at about the same horsepower.

If you don't change every piece of the TBI exhaust, you will choke the 350, anyway.

The '79 350 shortblock is capable of decent power with good heads, cam to match, exhaust to match, etc.