A904 rebuild - boosted W2 408

Hello guys,

I'm rebuilding a A904 tranny and need your opinion on this. Not possible to swap to a 727 as there aren't many around my area. The Car will be a 408ci/W2 boosted and the aim to reach at least 800hp.

I've ready that some drive racers would prefer using A904 due to reduced internal weight.

I have bought so far:
- Rebuilt kit with Rela Alto clutches and Raybestos steels
- Front and rear Kevlar bands
- New Oil pump
- High stall torque converter
- Transgo TF3 kit

Would like to know what else should I look for to take that much power? What would be the failure points...


Br,

How many disc does the front drum take?

Few things you need at least:
-Deep oil pan+oil cooler
-HD front band strut
-Billet aluminum low/rev servo

i also highly recommend:

-billet front drum, steel(for street/strip) or aluminum (for racing).
-bolt in sprag, or you should be sure your oem sprag is ok.

Your power goal is so high, and if it´s a pure drag car, everything can go broke, input and output shafts, planetary gears etc etc.
It also requires more maintenance after racing, you must change oils more often and inspect/change the oil filter, and bands and clutches too.

the list is endless

Definitely the billet front drum with the relocated ring groove to allow for an extra clutch and steel , the 25 spring return module , the 904 sprag is usually riveted in from the factory but the bolt in kit is cheap if yours isn't .

oh and you may need an assortment of different thickness retaining rings for the drums in order to get the correct clearance for the clutch packs , I was fortunate I was able to mix and match the thick front clutch's and steels with the thinner rear ones to get 6 instead of 5 in the front while also getting the optimal clearance there , plus I got a thick set in the rear to get the right clearnace there while beefing that pack up as well . Get to know a reputable vendor / builder they will be able to teach you a lot .