how much difficulty would be involved in swapping a transmission from a 2.8l a4 (manual) into my 2.8l a6 (auto), will there be a need for a custom driveshaft or can i use my existing one? thanks

 

Just making an educated guess here, but in every car I have ever done this swap in (non-audi mind you) the automatic transmission was electronically controlled by the ECU. When switching to a manual trans that is not computer controlled you must also swap out the ECU. Did they make 2.8L's with manual trannys? Because if it isn't a factory swap you will have to go custom, maybe taking the chip from the A4. That can run big money. Also consider that you would need a clutch master cylinder, the lines for it, a clutch pedal and it's assembly, and alot of hard labor! It really is a huge undertaking. I did it in a 94 Lincoln Mark VIII and threw in a Cobra 6 speed transmission, it required a custom shift box that extended the shifter to the proper location, custom ECU work, flywheel, clutch, master cylinder, etc. In total it was about $4000 in parts and $2000 in labor and other work.