Does anyone know if it is possible to put a 6 speed gs430 trans in a 99 gs400

 

Anything is possible with enough funds and time. Has anyone done it? Not that I've ever heard... probably not enough extra performance to be gained from the switch from the OEM 5 speed tranny to be worth the $$$$$.

I suspect ECU will be an issue.

 

i think i've heard of like 2 GS' ever that have done a swap.. don't know details though.. i agree with dave.. i doubt it'd be worth it lol plus it's so time consuming and yeah the ecu will probably be a big problem.. won't that take away from the luxurious-ness of the lexus?

 

K - he's actually asking about the 6-speed AUTO from the 3GS, not the 6-speed Supra Getrag Tranny