t56 major issues
Installing the flywheel and pressure plate requires torquing sequences in cross pattern. You might have impacted the crap out of it. Removed clutch and check disk wear and do the proper sequencing.
with tty gm bolts
First pass 15lb
Second pass 37lb
third pass 74 lb
Clutch to flywheel
Stock
52lb
The above has to be done as above to avoid:
warping
stripping
loosening
It is possible that the clutch is the root of your problems. It is also possible that it is self inflicted by using an impact wrench.



