1992 Dodge Dakota 5.2 Magnum advice

Lower gear is more torque release but high rpm's and reduced top end.
The exhaust manifolds can be OK but the actual units you have I am unsure of. There is a set of big 2-1/4 (IIRC) exhaust outlet manifolds.

You would need ether to be flashed with a super charger and the MP computer is only good for the mods they speced.