What should be my next mod?

[Silver5.0]

I have a 91 gt 5.0 with 3:55's, rear disc brakes, mac headers, flowmaster cat-back, 190lph fuel pump, adjustable fuel pressure reg, hpm lower control arms, racecraft springs, strut tower, g-load brace, TCI street fighter tranny, brazed converter, underdrive pulleys, k&n air filter, 9mm wires, ngk plugs. So now I'm wondering what should I get next that I would feel the most gain from, I can't afford heads yet and I don't want to do a cam until the heads, So would a black magic fan, C&L 76mm, X-Pipe, msd ignition I don't know? Thanks