727 No forward or reverse

Unless your running a lot of power or the trans has a bazillion miles on it it's not often that the planetary sets fail in a 727. You'll probably find that your planetaries are 3 pinion design. The older 727's had 4 pinion sets. If your running over 500 hp I'd find some 4 pinion planetaries and put in it. Be warned that the big block trans you found for parts may or may not be compatible because they changed the output shaft spline angle (on the front end)a few times during the run. They also changed the front drum and pump stator a few times so you have to be careful when swapping in parts. If their the same vintage plus or minus 2 yrs. you should be fine be farther than that it may be an issue. You could have popped the seal in the rear clutch pack which would have caused no forward yet reverse would have worked. Alto are real good quality parts IMO. Make sure and change all those bushings and tighten up the planetary end play and the total end play. Do not use the factory serv manual specs, they are very sloppy. To tighten up the planetary end play you'll need some planetary shims (may only need 1 but it might take 2). To tighten up the total end play you change the front thrust washer to whatever it takes to get it down to as close to .020" as you can get it. For me, 99% of the time it's taken the thickest thrust washer available which is .102" and that usually gets it down in the .025-.035 range. If you need any parts (small or large) I'd think www.bulkpart.com would be able to ship to you. I've bought from them a lot with decent luck