Skip the roller cam on a 350 and save yourself a ton of cash. Go with a K2801 (or K2802 cam if you have a manual trans) and a Quadrajet Carb. A 750 hooley is too big, even if it is rejetted. Jon (Carbking) knows way more about it than I do, and I apparently know more about it than the guy that gave you that advice. At least I think I do. And there for I am.
Use the E-Performer NOT the Performer RPM manifold.