I did not look back to find the cam specs but any time I hear 112,113 LSA on a N/A BB Mopar I cringe unless it is for power brakes.
All the BB I've play with N/A except one B1 bracket motor liked cams ground on 110 or narrower LSA, the B1 motor had a solid roller race cam ground from Koffels on a 111 LSA installed at 109 ATDC on the intake lobe and it made 920 HP at or around 7000 RPM with single Dominator carb on a cast single four barrel B1 intake
Have you done a compression test and or a leak down test on all 8 cylinders?
If not I would so I could be sure none of the intake valves are staying opened or bent
383 motors are a short stroke motor so they don't have the torque or power that the BB do so to get them to make good power you have to revved them up (above 6000 RPM) and keep them revved up in the power band