Our Tracker is a base model (LSi package) 2dr.

Our Tracker is a base model (LSi package) 2dr conv. With 3spd automatic. My question is: There is a 4spd auto trans available for other yr models. Can the 4spd trans be easily swapped into the 98 Tracker. I'm guessing that the 4spd model is an overdrive unit, which our little Tracker desperately needs. The car is screaming at 5Krpm going 70mph, definitely needs to shift! If you do not have the resources to find this answer, can you point me in a direction where I might find out about this transmission swap?