904 Questions

The 727 is a shoe in. A stock rebuild with a shift kit and convertor to match will live forever. But, they are heavier and take a bit more power to run it, plus you'll need a new driveshaft as it's longer than a 904. The 904 has a lower first gear which helps a torque limited 340, and it's lighter plus less of a power draw. However, the flaw I hate in 904s is the high gear clutch piston return spring which can uncoil and lose tension with repeated high rpm shifts. That leads to overlap between 2 and 3 and eventual failure. So the fix is to replace the forward clutch retainer with the billet steel replacement that is machined ffor the 727-type spring setup. It also prevents the retainer explosions, and allows more clutch discs and therefore more power transfer capability. If you have to do either, the 727 will be cheaper just because of the clutch retainer.