My 383 was like yours except mine was auto in a cuda. I ran the lunati 00032 bracket cam which is a .480 lift 292 advertised duration 230 @ .050 and had LSA of 109 I had 10:1 compression, reworked 906 heads, and stock manifolds, and a 750 cfm edelbrock (should have used 800 AVS instead). I had to go with headers to get the engine to breath and a 2800 stall convertor. The cam was good from 2500 on. My gear was 323 but could of used at least a 373 or 391. Idle was good with alot of lumpy idle but good with my convertor or in your case it should do fine with the 4spd. The car had all the power I wanted from out of the hole to top end. I know the performer rpm or the holley street dominator are better but I used the performer since I had it already when I rebuilt the engine.