Maoy,
Thanks for taking the time to respond. Funny you say this about the gears, I just finished installing the 39t gear and now I have 23/39 for second and 17/43 for first. I may need to rethink the first gear ratio.
I have done a lot of mods also (not for show, just for go) but after reading this I am not sure I did the best things.
I have the HPI 3mm “Super Chassis” and have used the HD CVD shafts from GPM for the centers and outdrives. Are you using the GPM’s or are there better ones to be had and where did you get a 4.5mm chassis?
I wasn’t sure I could get the 37t gear to work or I would have gone with it. I own a mill and a lathe (and several Dremel tools) so I have the ability to do the necessary mods now that I know it can be done.
Anyway back to the shop. If you have any further suggestions please let me know. I was just about to give up on the RS4 ever being a hot rod. The main reason I want to use this car is you can get parts for it anywhere and I have got the handling very well balanced using 37 shore foams on the street.

John