[Alan Roehrich]

The o-ring most use is a servo o-ring from a 700R4 or 4L60E. But the problem with the release on all but one of the 400 brakes is not in the drum or the clutch pack, the problem lies in the passages that they use.

At 0.010" per clutch, you'll have only 0.050" to 0.060" clearance in the direct drum. Now 0.020" per clutch is too loose, at least it is for me. I actually use a 6 clutch pack with about 0.080" clearance. It seems that most often when you exceed 0.080", you end up with a 2-3 shift flair, and the car rocks forward a little when the brake is applied. Now, 0.050" to 0.060" is fine for the forward input drum.

If you go the cheap route, and use standard steels, note there are 2-3 different thickness steels. You can adjust your clearance that way. Also note that some drums cannot be used with shorter pistons, as the steel that sits on the piston can drop too low and rotate, then it will not apply.

I've had a lot better success, and longevity, from the Alto Red Eagle clutches and Kolene steels. My 350, 400 and PowerGlide transmissions go forever between overhauls, with no problems, and even after a couple of seasons or more, they look like new. I use the Alto stuff in every clutch pack.

How you set one up depends on what brake is in it. ATI makes a good budget 400 brake, and the TCI isn't bad. We had trouble out of all of the others. With one exception. The absolute best brake for a 400 is the Griner, even ATI will tell you the Griner is better than theirs.