Quote Originally Posted by Sabrewings View Post
A little more than the differential, but once that's done then yes (strength wise). The differential, sun gear, differential housing, and output shaft are all needed to do the full conversion. The only reason the output shaft is on there is the HD one is a bit longer to fit in the HD diff right. Not a strength increase.

The only difference between a 4T65E-HD and a non-HD with the upgrade is the drive chain. Again, not a strength difference, but the gearing is different to provide a different gear ratio to the HD. It actually works out easier for non-HD owners since 3.29s only require a diff upgrade. For HD owners to get 3.29s they have to take their side cover off and swap the chain/sprockets.
Thanks I'll have to look into it. I'm thinking of maybe building the trans first. From the readings it seems the higher mileage trans have a pretty good amount of potential problems that I'd like to eliminate to the best of my ability.

Now I've never built an automatic transmission before, only reallly worked on the manual trans in my talon. Is this trans a pain to work on? Any advice?