has a lot of info, put together mainly by Jack Travis, Pres of the EA-ED club.
Basically EA came out with 3 different engine varients and 3 different trans combinatoins.
3.2l CFI:90kw Single throttle body electronic injection - quite rare and quite slow
3.9 CFI:120kw Again single throttle body injection system, probably the most common
3.9 MPI:139kw Standard on all fairmont ghia and optional across the range. Multipoint injected and the top of the range.
3A: 3 speed auto, slow inefficient and horrible (I have one
4a: 4 speed auto, introduced in '90 anniversary edition I think
5m: 5 speed manual (t5) pick of the bunch for performance
If you have a 5m 3.9 MPI performance will be very good. A 3A 3.2 CFI will not be very good at all.