What is my Heath tune going to do with the ATT? Is it going to smoke real bad? (I HATE 'rolling coal'. Don't even get me started on that topic) My crossover pipe is heat wrapped so it shouldn't cool off as much as others. Maybe it'll help light that turbo sooner?
On the upside, I thought the engine braking feature Bill puts in his tunes worked pretty well. Better than I expected for just keeping the TCC locked up on de-cel. I just want it to stay locked longer, like down to 25-30mph instead of 42.
Very interesting about the 4L80E problems. I hadn't heard about this before. Are there any fixes for the clutch issue? I'm sure there are better input shafts. That trans has a good rep, at least as a TH400.
I would get a custom tune for the ATT because you are completely changing what RPM you get boost at and have more ability to burn fuel at high RPM where the GM8 would just smoke. It's not just a turbo swap, it's a major change to the engine that a tune will get the most out of. (Including smoke control.)
Consider I towed 100% of the time so anything weak I will find. Now the 1993 is a hot rod and unloaded I still like the big turbo merely looking for ways to avoid the variable turbos that are the modern solution.
It's the only weak point I found 2nd to the factory converter clutch. Otherwise you are looking at some custom work to build an adapter and put an Allison behind it. There was a 6.2 with this done for sale awhile back. It's in the closed classifieds.
Grade braking with the TCC locked - you are trying to hard to do this! That is why GM has the TCC unlocked during manual compression braking. Look up overrun clutches and see how small they are. I understand one place makes 3 frictions for this clutch rather than the 2 normally in the 4L80E.
Even MT isn't a good answer to engine braking as MT clutch manufacturers don't recommend it as a clutch is designed to torque in 1 direction only. However on a Dodge it's the only option as the older auto's were not recommended for engine exhaust brakes at all. So add some clutch wear...
It's the 2nd to last question.
http://www.southbendclutch.com/troubleshooting.html