The main reason I wanted to switch to the 6 speed drum was because I thought I saw the 6 speed drum doesn't use the balance piston like the 5 speed drum does, no balance piston results in much less chance of tieing up the 3-4 shift. Which i already know my c2 clutches aren't ideal (8 red eagle clutches) as apposed to 7 clutches in a much better laid out trans "kit". So I figured between a 6 speed drum and a properly spec'd set of c2 clutches, I would have slim to no chance of tie ups.
But if a properly set up 5 speed drum is acceptable then I will stick with what I have and refresh the trans with better parts this time around. I'm sure my c2's and c3's have seen better days. Stock tcm tuning has hopefully kept my c2 hub and planet splines in good shape.
8 clutches in C2 has not helped your tie up.
Remember that the Transgo shift kit was designed for a stock trans. The bottom C2 piston holes that you restrict with the cup plugs eliminates what the balance piston does. So in theory; you have gone from about 11" of apply area to about 19". so to speak. Doing this caused a violent 3/4 shift. hence the stronger return springs supplied for the C2 piston to tame the shift down and stop the big tie up that was caused by this mod. Now we add 8 Alto Red Eagle clutches which are far more aggressive than the 6 Borg Warner clutches and all bets are off. You now have the worlds biggest tie up.
Anytime you feel a hard shift in a Allison trans; the rear wheels locked up for a split second. Not good.
What a lot of tuners don't realize when they play with TCM tuning and think they cleaned up the shift and made it feel more like a turbo 400; they screwed it up. It is a proven fact that you will go faster with defuel than messing with it and locking the rear wheels up with your so called tuning.
The Allison needs to go into neutral for a millisecond to make a clean hand off to the oncoming clutch. I've seen a Allison engineer play with the TCM adjusting the ramp rate on the trim solenoids and clean up the shift very nicely. We can not do that.