Mopar Magnum

Headers are a BIG plus in the power department. 2-1/2 exhaust pipe should follow.
Porting the head would also be a big help. If the heads have a "R/T" cast I to them, those are very good heads to port.
If those to items do not give you enuff power, change the cam.

Does your torque converter match up with everything.
What gears are in the rear?