Originally posted by Yankeyspeed:
Which manifolds should I go with,the 2.5 or the 3 liter?
2.5 manifolds, because the 3 liter ones won't fit. Headers will fit also without problem. The only real problem you'll face is the injectors issue. You either need to find a side feed 19-24pph unit, or (this way's easier IMHO) swap out some of the wiring harness, the fuel rails, and injectors from a newer return fuel system car. A customized ECU of some sort will also be needed (i.e. Superchips, Apexi, or some stand alone unit).
OBD-I is actually easier to "fool" because it "knows" less about the car's functions. It also makes you rely on a little more tuning knowledge rather than a computer system to tell you what to do.