727 -> 904

I agree with Guitar. Rebuild your 727 and stay with reliability. Yes the 727 will use a little more HP to turn it but it's worth it in reliability. As far as how much HP difference there is. I read an article a few yrs. ago that did comparison of all the major manufacturers different automatics and how much HP they required to turn them. The 904 required 42 hp and the 727 took 55 hp so there was only 13 hp difference.