The f150 forum has detailed info on all this stuff. I had a 92 f150 until recently. You probably already know this, but unless you swap in a different cam, the mustang motor sucks in a big heavy truck. The factory f150 cam of that year was bad enough, but the mustang cam makes it even worse.
Lots of good info on these trucks on the forum...including a how-to thread on performance upgrades for a 302 f150 (cams, intakes, maf swaps, etc). Well worth the read.