1977 904 horsepower limits?

have been using stock disc and steels...Kevlar bands...billet rear servo in a few of them MOPAR 904 500 42RH 42RE TRANSMISSION BILLET REAR SERVO KIT, DODGE, PLYMOUTH AMC | eBay some I use this servo..actually been upgrading to the MrRandy servo went I rebuild them...think I got 2 or 3 with that servo and I use this servo for the most part...42RE 42RH A904 Transmission Sonnax Rear Servo Piston 22912A | eBay

all the 904 with transbrakes (Tranzact of Indy) use the 24 spring kit in the front clutch...all the front clutches have 5 disc in them....and If the pump gear looks iffy...I change it out...I have used both Teflon and steel rings...No accumulator is required with manual valve bodies...I have one trans with a ATi wound front clutch spring but it has even to hit the track since the car is still waiting for me to work on it.

I don't buy kits...I order parts in bulk....like 10 disc..10 steels...then half dozen lip seals...and pump seals...so I always have enough parts on hand should I need to repair a transmission..