Question for the Tranny guru's

[Cory_Langford at bcit.ca (Cory Langford)]

I need some opinions on building a tranny for the racer..

Rules state that I can not modify the dif. external housing but that I can
modify/change the dif.  So I figured a quaife would be in order.

I have to keep the same gear ratios that were in the car when sold (so that
means the FF trany set), but I am allowed to change the final drive.

So what advantages/results would be had by changing the final drive on?
What final drives would be available?

I have never torn apart a tranny so I am not even aware of what would be
involved in changing the final drive (if done I would send it to a
reputable shop to do it).  Is it even possible to take parts from say a 4y
or 9a and install them in the FF tranny to get the smaller final drive?

TIA


   Cory Langford
   Roco race car on its way 8^)
   81 1.8S (for Supercharged)
   78 1.9L 8V Turbo
   86 2.1L 8V Turbo
   68 Ghia
   95 Eurovan