Many Ford cars the same age as your truck had roller 302's. Your block may be compatible with factory roller cams already. The biggest problem may be that too much of a cam change might confuse the computer and make it run badly. Crane makes a computer-compatible cam (pn 364211) that's a little bigger than a stock low-output 302 roller, but smaller than a stock 5.0 Mustang cam. I hear it's similar to a late-'90s Explorer cam. Crane told me it raises the operating range of the LO 302 by about 500rpm. Other companies may have a similar grind.
If you still have single exhaust, freeing it up should help quite a bit. It did on my '88 T-bird, and all I had to do was gut the big single catalyst (it already had dual mufflers). It gave me more power from idle to ~4000rpm, instead of running out of breath at 3500.