904 race build

I got 5 904s in use in bracket cars.....4 with transbrakes and 1 foot brake.....

The 904s with transbrake all have 5 thin clutch disc in the front drum....I use the thin disc and steels from the rear drum....you need a minimum of .060 clearance with the 5 disc....I have had to get the pressure plate cut about .020 on several of them....
I also use the 24 spring kit that replaces the large wound spring in the front drum......a cheaper route is ATi make a single spring that is wound the correct way to keep the front clutches from slipping at high rpm......
I generally use stock steels and stock disc or high energy clutch disc....only used the red alto and kolene steels once...

Front and rear bank I use Kevlar bands.....the rear are the double wraps....
I use the 5.0 kick down lever on the front band along with a heavy duty band strut......
Front servo is stock....Rear servo is a one piece billet design....
re.
The transbrake manufacturer says use Teflon sealing rings on the pump stator because of the line pressure,
I replace the pump bushing...the front drum bushing..and the rear tail shaft bushing and new seals on both ends.
Pump gears are usually stock unless I see something....then I replace with harden gears ......
the 904 stock have a bolt in sprag......just get a replacement roller/spring kit for 10 bucks...

I dont buy kits since the kits dont have what I want.....they give the thick front disc and steels..I usually buy from What ever it takes trans....i order individual parts....and keep enough extra parts to rebuild a 904 on stock if needed...plus I have one complete 904 spare if needed too...

that is my basic trans.....i rebuild them myself....they are simple...