rams horn

Hi, I have a 57 Chevy with a 327 SBC from 1965. It has original 2”, 57 style cast iron Ram horn manifolds installed. I would like to replace the 2” ram horns with a new set of the same style, but 2-1/2” instead and then add a 2-1/2 exhaust system all the way to the back. Like the ones in the...

Alright! im getting brand new chrome exhaust manifolds and i have a few questions. Would I okay getting manifolds with a 2.5 inch outlet and then have an exhaust shop attach it to the rest of my stock 2" exhaust? Do the crossover pipes on stock dual exhaust systems really do enough to justify...