Transmission Willie GM 4T65E Transmission fit my 2001 S 80
 

Well A GM 4T65E Transmission interchange with my 2001 S 80

are you thinking of taking a transmission from say a 2004 XC90 and fitting into your S80? What engine are you going to use? Aside from fitment questions, I'd raise a caution flag in getting the ABS to talk to the TCU and in getting the TCU in talking to the ECU...