I think with that 4.10 gear and 3500 stall . The biggest camshaft I would run is the Comp CamsXE284H . That cam is 240/246 dur at .050 with 507/510 lift and a 110 L/S . Do remember this is a 383 not a 406 and make sure the rods have enough clearance to the camshaft . Many 383s have broke cams from not being set up right . For your intake I do think an air-gap Dual-plane Like the Weiand Stealth Air-Strike will add to the HP and low-end Torque . But I would sell that Holley 750 V/S and add the money to buy a 750-800 Holley D/P COOL