ou812 have to dissagree. A 727 has twice the clutch surface area when you take the diameter into account. Also the gearsets and shafts are larger. The case is also stronger.

That said there is nothing wrong with a 904. Start building these powerglides everyone is bragging on and you will see the clutches many use in glides are the same as 904 just more of them in the race glides.

If I were going to take a shot with where your problem lies I would say in the valve body. Not a fan of A&A valve body so I may be bias. You could possibly just have trash in it in their defense. I gave up on 904's due to breaking the front planet never lost the band although you do have to stay on the adjustment more than in a 727. The proflites that run so fast are 727 cases with modified 904 internals and a ton of tricks. They set records everyday.

Try a Griner or Transact valve body after checking the case for leaks and fixing the problems at hand. Probably will not hear about trannie issues from you from now on. But, I fully understand when you loose trust in something on your car you can easily be beat. Carry a spare tranny and you will never need one.LOL

Leon