I just wonder if internals are different. Talked to several Supra trans builders that said if I sent them a trans they could verify internals. I believe I found the 340 has a few less clutch packs a the 343 in a few different locations. Those trans builders machine cases and change steel to increase clutch counts and there for contact area to hold high HP Supra builds that are north of 1000hp with the same family of trans. I’ve just never had the need or time. TC seems to be the weak link so far with the diesel swap community, that I have been more a part of.