MuuMuu101's 68 Dart, A Learning Process...

Its pretty obvious to me that it's installation error on their part, or some defective parts (something like the throwout bearing not returning). The clutch on basically any manual car should be releasing about halfway up and have some freeplay to the teeth.

Yeah, SilverSport Transmission says the T56 design is a tad different where the throwout bearing is supposed to ride the pressure plate. But they do mention that if you don't get your cushion measurement correct, it could cause clutch slippage.

See page 8:
https://shiftsst.com/media/wysiwyg/pdfs/2017June/MAG-00402_GM_Hydraulic_Manual_RevF.pdf