Intake manifold. Copied Elddebrock performer RPM.

Well, This is a deeper subject than I even thought. So Here is the real problem... I have a 67 B-cuda with a 69 340 LA solid cam Racer brown stiff springs 202 valves mild porting. Also have hi-perf 68 340 exhaust manifolds cast iron with TTI head pipes and exhaust 2 1/2. I am using An 340 victor intake with a 750 vac Holley. It use to have a 650 Mech and headers and ran much stronger. I don't want to race this car any more. I was looking for an easy way to tame this car down for street. (373 gears B&M hole shot conv)
I just picked up a Proforma 650 Mech. I just thought a dual plane intake would work better with the exhaust as is. I am considering a cam change, but I am not sure what on that either. what do you think?