Speed density conversion

[mustangLX92]

My car is a 92 lx.
Front Suspention- Motorsports springs 1 coil cut out. Lakewood drag struts

Rear Suspention- Southside Machine rear lower arms. Motorsports upper arms. Lakewood Drag shocks. Southside rear drag springs.

Rear End- 3.55 Gears. Alburn posi-traction.
31 spline axles.

2 1/2" Flowmaster exhaust. 1 5/8" Motorsports headers.

GT 40 Upper and lower intake manifolds
GT 40 heads. crane roller rockers
X- Cam, underdrive pulleys, Speed density comp., 110 g.p.h Fuel pump.

For some reason it is speed density. I know converting to mass air would be a smart move.
What is the most cost effective way to do this. With my combo what kind of results would i see.