It is cheaper to buy a rebuilt engine than to rebuild it yourself. They pay far less for parts and machining. You buy the pistons before the engine is bored, so the bores can be made the right size. If the engine does not need boring, you use the existing pistons. If you are just freshening up a 350 with rings, bearings and gaskets, that only takes $200. You can buy nice heads for what it costs to rebuild heads for performance. The 1975-1980 Nova can use suspension parts from 1970-1981 Camaros and firebirds.

You would need the pistons that match the engine you're building. There's really two options for you.

First option is to have the machine shop order all the parts since they will know the specs of the block.

Second option is to pay someone to build it for you because frankly, choosing pistons is the simplest part of buying parts for an engine. You didn't list the type of engine so we don't know if this is a 4 cylinder or a 350 V8, a stock rebuild or a performance one. And I'd hate to see how you select a camshaft...

Buy a rebuilt short block the same size and type of your engine, cheapest way. When they rebore them, the pistons are usually .20 or .40 overbore.

be nice to know what motor . but what ever new bore is no problem getting pistons to fit

Beautiful car by the way!I shop at www.carpartsdiscount.com you'll be able to find everything you need there.

So if I were to theoretically rebuild a 75 nova (I'm saving for a project car) and needed to rebuild the engine what pistons would I need? Assuming I have it over bored at a machine shop, how would I find the proper pistons? Will I be able to find new after market ones that will work? Or would I be better off using what I have?