After some searches I find there are more than a couple of pitfalls in trying to upgrade a 1972 904 to five clutches, in order to handle the 408 I built. With 520 torque, I want to be sure The 904 will live a long life. I plan on using a full manual VB, and will take it to the track with slicks a few times. Who can steer me right and sell me all the right parts?

We got all our 904 parts from Cope Racing:

http://coperacingtrans.com/

what frictions are you using? think you can fit 5 if using the thin ones.

As far as parts... Pro Trans is right across the desert from me so I've been using their stuff here and there.

Greg,
If you aren't bracket racing it every weekend, most of the stock pieces will do the job.
1. Run the thin clutches from low/reverse drum in the high gear drum
2. Multi-spring pack to replace the large wound spring in the high gear drum.
3. I went with the aftermarket front pump gear with the larger lugs to reduce the chance of breaking the converter snout, but I never broke one previously.
4. I added the 300M input shaft on my last upgrade, but I've never broken a stock one.
5. If using a RMVB, try turning up the line pressure a little. the biggest problem with the 904 is burning up the high gear clutches, so more clamping force helps.

I've ordered stuff from A&A, Cope, and TCS. All charge shipping, so try to know what you need and get it all in one order!

This may help some Greg.


https://board.moparts.org/ubbthreads/ubbt...tml#Post2400634

If you use the thinner cluthes and plates you can get five in a 4 plate drum or if you have a 5 you can get 6 in those and yes turn up the line pressure call Rick Allison at A&A I would also put in a 4,2 lever

Rick Allison at A&A

Another vote for http://www.aandatrans.com/. They have helped me with 727s, 904s, and 518s. They have the parts AND the knowledge.

I built a 80s model 904 with the better case and steel planets Also a lot of the later 904s came with the 5 disc drum so I could use the thicker clutches.
I got all my stuff from Cope.

Thanks, guys! And to think in 1985 I let an a999 equipped 360v8 1977 fury go to the bone yard! I could have used both motor and tranny!

Most of the higher end tranny builders on 904 buy their custom high end race parts from Dave Smith at Pro Trans, he has them built and wholesales them to other volume dealers
Call him first for the best selection and prices 661-940-7400

I heard he gets most of his stuff from Rick no idea if its true im sure you will be in good hands on who ever you use

They share quite a few parts back and forth Scott. Pretty sure both realize the volume is not there to do the r&d on each and every piece. I have been at Dave's shop a few times and they do manufacture a lot of things "in house".