318 performance question

I pulled the heads on mine and opened up the intake ports considerably. I raised the roof of the ports, opened the pushrod pinch, profiled the guide boss and bowl blend. I have a performer 318/360 intake port matched to the heads and a '74 440 thermoquad. The cam is a mopar performance .450 lift 260 duration. The bottom end is all stock low compression '83 318 out of a stick shift van. No fancy exhaust just stock A-body 318 exhaust manifolds and 2" dual exhaust. Stock electronic ignition. Way faster than it was stock. You are not going to get that much more power without changing the cam. Also the stock timing chains have nylon toothed cam gears that are not very accurate and tend to wear the teeth off and jump time. Definitely worth replacing