I would recommend performer rpm air gap and 1 3/4" header to start. Heads flow 250 @ .500" according to Edelbrock. Cam is on the money as long as you are using oil with proper additives. I would change only those things and tune ignition curve carb to see if first 330' can be improved. This car should 60' in the 1.60 range. I am also assuming that this is a street car. I owned a very similar car that ran 11.60's at 116 open and 11.80 @ 113 closed exhaust at 500 ft. altitude in fair air. I have dynoed and raced these types of combos many times. The dual plane will not hurt the top end of this engine at all, and will help hit the converter harder on the launch. JMHO of course. I am fairly certain many will disagree with me.