Advantage with a 350 Chevy is you can get parts for them much easier,easy to work on and the 350 Chevy is the cheapest to build over a 304 and a 360.Plus the parts interchange a lot with a small block Chevy.You can take off a starter off a 4.3 and install it on a 350 Chevy.The 350 Chevy is the most popular crate engine out there also put in Ford,Dodge and Plymouth street rods.