I wouldn't want to. There may be more of an aftermarket for the 65, but the 60, in stock form, is much more durable IMO.

Don and I have discussed this at length, by watching all the failures here of the two types of trannies. Guess what? We haven't seen any abnormal failures in 96 SSEi'*, either. Most 60'* long outlast the 65'*. The 60 is more reliable, despite the lower ratings GM puts them at. More performance transmissions are becoming available for the 60 every day, too.

That'* good to hear. I was just thinking that if my tranny goes, I could replace it with a beefed up 4T65 from intense and not have to worry about putting more power through it.

Your PCM and wiring harness aren't set up for it, so that would be alot of work.

How many miles on your current trans, and how do you drive it?

100,000 miles and driven fairly hard; very few burnouts but a lot of WOT runs. I've only had the car for a few months and the previous owners were an elderly couple so I don't think they abused the car too much.

Is there any way to make the 4T60 stonger while rebuilding it?

There are updated valve bodies, and other internal stuff that will naturally happen when you get a rebuild, but the output shafts and input shaft would be custom. Adding an additional tranny cooler will help, and getting a flush done once a year or so would lengthen it'* life under NORMAL circumstances. I've heard stories of flushes causing problems, but I've always had good luck with them.

Perhaps the best thing you can do is to upgrade to an LSD. The differential is usually the part that gives out under the SSEi'* with the 4T60. An LSD would protect it.

A bigger tranny cooler and a LSD sound like a good idea.

Edit: Nevermind, I found everything I need at seriesoneperformance.com.

Thanks for the help Will.