Manual Swap

Currently, I have an opportunity to swap 6spd manual transmission in my 3.0. The options are to put 6spd manual from 2004 A4 3.0+diff or 6 spd manual and dif from b6 S4. Which setup would be better in terms of performance?

Also, if i want to leave the original ECU that was chipped by JHM, how can resolve the speed sensor problem?
My car is 2002 and the speed sensor is located at transmission. After 2003 the reading is taken from ABS. is there are any ways to reprogram my ECU, so i can avoid loosing JHM software?

Thanks for help

Why are those your only 2 options, ideally you should use a 3.0 transmission, 01E if you can the speed sensor is in the transmission. It will also give you the best performance gearing and its a good strong transmission just make sure you get one in good condition so you don’t run into a problem with 1st and 2nd gear synchros. There is one that is JHM rebuilt on Audizine for 1200, if that’s the price shipped its a pretty good deal.

The best thing you can do is just try to put what came in the 3.0 as far as confirmation wise. This way there’s a better chance At getting jhm to get you a easy ecu solution

there are two donor cars available. I do agree that the beast option is to use the parts from 3.0, however not sure if the gear ratios and final drive will outperform S4 setup. With regards to 1st and 2nd gear synchros,how long they typically last under normal driving? The donor car has 150k. It would be nice to install all JHM goodies at the same time,however it is over my budget. :-\