3.9 Stroker
I had a 5-speed '88 Sport 4x4 when my wife and I started dating. Loved that truck and the 3.9 moved it along pretty good with the 5-speed. Looked at that M1 intake but never got around to doing it. Truck got hit and totaled in our driveway a couple months before we got married. Ordered a '96 V8 to be it's spiritual successor and still have it.
If I still had that 3.9 truck I'd probably look at a TorqStorm supercharger to wake it up.