A904...does it need a rebuild?

If you have no 3rd gear or reverse it's a fried front clutch pack. Needs rebuilt. Why do you want to swap to a 727? 904's are plenty capable of handling a lot of power (400+) with very little done to them and they don't have as much drag as a 727 to suck power out of your engine. That means better performance and better gas mileage.