SO what did I do wrong to only get an ave of 30K out of a th400 and early 4l80e tranny? I had a 700r4 go longer along with a 4l60! Probably the slow speed, steep grades etc I did frequently. The 4l80e/th400 is one of the tallest geared auto's with a 2.48-1 first gear. THe 700r4/4l60e auto and allison have 3.1 first gears. SO better take off from a start without issues of heating the tranny up!
GM used an NV4500 in the 93-2000 trucks behind the 350/454 and 6/5td, Before than a muncie 4 spd. That is a better tranny than the 4l80 if you do a lot of towing. The 93 and 94 had a wide ratio, 95 and later the narrow ratio like Dodge.
Marty
