Hi For my work car, I have a 1997 Olds LSS with the L36 and 4t60e. This is the original, unaltered tranny and has never been out of the car. I do a pan drop 3x /yr with the resultant fluid swap and filter change during one of those instances. The car has 244,000 miles on it. The major differences between the 60 and 65 is that the 65e does not have the vac modulator as the 60e does. It relies, instead on solinoids to determine shift points. There are a few enthusiasts out there that believe that the 60e was a stronger box..at least in the late 90s. The 65e came out for the '98 model year.