the biggest thing would probably be a set of gt40 / gt40p heads and intake off a 96-01 5.0 explorer/mountaineer
sometimes junked mustangs have exhaust, aluminum driveshafts, and other bolt ons that you can get for cheap (i got a bassani X for $15, aluminum driveshaft for $70, a free tri-ax shifter that came on the tranny, and a few other things)
happy hunting