I'm rebuilding a 350 to put in my camaro and the block came out of an 81 camaro, I was wondering if I put a new cam in if I would have to get new pistons.

 

No you won't need new pistons just because you're putting in a new cam but if you bore out the block you will.

 

thanks. i just wasn't sure because of the compression. And i have another question, the gear ratio that the cam calls for is 3.73 or higher and i don't really know much of anything about the rear end so how would i change the gear ratio?

 

With a low compression engine, you don't want a cam with too much overlap. So, don't go hog-wild there.

The gears aren't directly tied to the cam selection. It's more of an overall performance indicator, particularly 1/4 mile. But, to change the gear ratio, you need to change the rear end gears. Which requires special equipment and skill, so it's typically best left to a shop. The Transmission and Driveline forum will have more information about gear changes.

 

Requires a new ring and pinion set in the rear end.