My first car was a 71 pontiac G.T.O, it had a 400 ci engine, but i blew that up, so i put a 455ci out of a 68 gto judge, 500 hp from the factory. I bored the cylinders 30 over with black jack pistons, then had the engine balanced and blue printed. It did low 12 in the 1/4 mile. Id kill to have that car back. I got it in 1986 and sold it for 15,000 in 1992. Im a anto tech by trade so I know your 70 and a half will be awsome, its good to be a gear head.