I was doing some more research and from what I have read the input shaft can be a victim at around 800HP, next is the 2-3 shift where you will see wear. I say run what you brung! lol There are lots of guys hammering on the 904, you don't really hear of any horror stories like you think you would.
Can a converter that was built for a 904 be sent in and have a new snout installed so it fits the 727? Bolt pattern etc is the same on the flex plate so I don't see why that could not be done on the cheap to help costs if you go to 727 later? Has anyone done this?