Not sure if its possible my friend has a 2005 Audi A6 3.2l auto and the motor blew, so hes looking at swapping the 3.2 for the 4.2? is this even possible and what would be involved. also looking into going from automatic to manual

 

Lol, Not going to happen. There is no manual transmission for a 2005 A6.

Swapping for a 4.2.... Unless the transmission is exactly the same for both, which I doubt. Going to cost more than the car is worth. You have to replace prop shaft, rear diff, all 4 axles... ECM, TCM, complete exhaust. It's like Pandora's box of problems your unleashing.

The only way to know is to compare the transmission assembly codes with a 3.2 model and a 4.2 model to be sure.