727 build fail

Rebuilt my 727 and now it seems to be binding in two gears occasionally. Mostly stock build with the exception of a TF 2 kit in valve body. I have build a dozen 727's and never encountered an issue like this.
Its felt kinda sluggish like it was dragging. Drove about 5 miles and slowed down for a car that was turning. When I accelerated the rear wheels locked solid for about a second and then it went on its way. Drove a few more miles and got to a place where I could safely test it. The lockup occurred several times again then I parked. it.
The only thing I can think of was the rear clutch pack clearance was rather tight. I should have ordered the thinner plates but in haste to get the car ready for a show I just went with it. Tried a variety of selective snap rings but it was still not where I wanted it.
Any thoughts on how to proceed? I was thinking about swapping the valve body out first to rule that out before pulling the trans. I have a nice turbo action reverse manual I can throw in it.


Just off the top it sounds like a shift bind where two gears are applied at the same time for a second or two, because a gear is applying while before the last one lets go.
It happens frequently with the TF2 kit install when shifting automatically, and there are ways to deal with it as some have hinted at already. (it's called shift overlap)
Tracy can help with a lot more info if he knows exactly what it does and when it does it.