727 or 904?

Either transmission will suffice. IMO, if you already have a 727, I would use it. Yes, the 904 may take a few less ponies to turn, but the 727 can be built more reasonably than a 904 to hold up to that kind of power. 904s are great transmissions, but it does cost to make them stronger.

If cost is not an issue, then 904 all the way. If budget is a concern, I think the 727 will win out.