NA auto is Jatco RE4R01A TT auto is Jatco RE4R03A From Z1: http://www.z1motorsports.com/PDFs/NATTconversion.pdf NA stall 2450-2850 TT stall 2950-3200 Different ATCU, shift points etc. Pretty sure but not 100% on these 2. Converter/flexplate has different bolt pattern. Output shaft differnt spline count.
Is there any difference in these auto boxes as the years go on? I noticed some atcu part numbers are different between years. My auto is from a 97 NA. The sump of it has a different design compared to the old 90' NA box I had from factory.
Had a bit of a look in FAST and for both NA and TT. There are a few different part numbers for each and usually change both the ATCU and transmission part number at the same time. There was a change with the NA pan 07/89-04/93 and after that the pan gasket and fasteners changed.
Flex plate and converter are different - larger converter on the TT, different output shaft size and spline count (can swap to match the front half of whichever auto you are using) and also hardlines to the cooler are different. I fitted a TT auto to an NA a few years back. Worked fine with the NA ATCU.
