>>>>>They have the same rear sprague and geartrain designs. Identical except in size of parts. Both will explode if the sprague is damaged and they run a stock sintered iron forward clutch drum.<<<<<
It wasn't the sprag that was the offending part; it was the way the sprag is anchored to the case that was what caused the problem in 727s, according to Len. I have never had a T-Flite apart, so I am only repeating what Len said about the problem. You, obviously have hands-on experience, which puts you miles ahead of me when discussing this issue. All I can do is repeat what he said, which basically was, the 904s don't explode because the rear sprag anchors stay put; the 727's don't, sometimes. If that's wrong, I apologize for dissemnating bad information.
>>>>>But 904s were never considered good for race cars until racers really looked into the driveline for lower ETs.<<<<<
That's true, I am sure. But, when ProTrans started building and selling their $5,000.00 race transmissions, they used the 904 exclusively, which says a lot about its power-handling capabilites, since a lot of their transmissions go into 800+ hp, 426 Hemi-powered Super Stockers.
Bill