Dyno'ed My 360..it's a pig..what next?

Cheap fix... You have enough carb to run well into the 13"s. Your carb needs more pressure, 7lbs. 4 corner jetting is not for a street car, it is for WOT only. 1 5/8 header are fine.
Check your compression on the engine, check on each cylinder. If they are low pull a head and check your piston and valve clearance. Shaving the head or using a thinner head gasket can raise your compression, with low cost, Possibly need a shorter pushrod to do this, depends on how much you cut. Take out the valves
and "clean up" those ports. These are all basic parts with out to much investment.
You have enough carb to do what you want there, it just need tuned in.