Originally Posted by race24x

As a GM tech in the period around 1988 when the 4 speed autos came out I can tell you if you constantly let your car shift from d to OD everytime you let up it shifts in OD and when you try to accell it shifts back down you will wear your trans faster. for those of you with 2.73 gears at a guess I would think your 3rd gear is pretty close to a guy in 4th with 3.42's I cant be sure on that without doing the math and I aint gonna do it. It was recommneded by the factory that you run in d until you get over 45 MPH to cut down on the amount of trans that GM had to replace.