A904 high performance rebuild--advice wanted

For a mild build you don't need the fancy clutches that cost 3x as much. Heat, lack of hydraulic holding power from floppy shifts, and loose build tolerances are what kills transmissions, not if they are red or blue.

The borg warner tan and the like are all you ever need.

A popular way to add that 5th clutch pack is to take the piston from the direct drum and have it machined down the thickness of the a clutch and steel.

Before you order anything, it would be wise to check end play before you disassemble and then check your tolerances so you can get the parts to tighten them up before you pull the trigger on a kit, snap rings, and most likely thrust washer, all inexpensive items, but not when you have to go back and do it again. Build to the tight side of factory specs.

Check out WITtrans.com, they are sweet and very helpful people, did I mention their prices are cheap as dirt?

Finally, go easy installing the piston lip seals, triple check everything before it goes back together, and air test your clutch packs and as an assembly! PM fishy68 for the picture of the test ports.