I am getting together a 686 that had broken the 7" TA Pressure plate and the TA clutch disc was bad as well. I got a sprag type TA, the HD 9 spring Pressure plate and the 4 pad clutch disc for it and a new TA clutch flywheel. After getting it all together I bolted the TA housing to the rear end and tried the TA lever after connecting the linkage. That TA lever is WAY stiffer with the 9 spring pressure late over the 6 spring. And in TA it's not releasing the clutch disc. You should be able to turn the input shaft backwards in TA, and I can if I have a vise grip on the shaft, but it's very hard and the disc is dragging. Just wondering if I have a bad pressure plate. I can't even move the disc back and forth on the splines in TA. I have a 460 split for a TA too and I can turn the shaft both ways easily in TA. So that one is releasing fine.
When I got the pressure plate and tried to install it the fingers were out too far to get into the housing. The 3 threaded bosses for releasing the pressure plate have springs over them on this 9 spring unit. I had to press the fingers down on my hydraulic press and put cotter pins between the fingers and the lugs on the plate where they pivot. After bolting it to the flywheel the cotter pins could be pulled out. The fingers seemed to press down hard even on the hydraulic press.
Is anyone using these and what kind of luck did you have. I thought I'd just upgrade to heavier parts, but 2 people I talked to tonight wouldn't use them again and 1 took it back out, because it makes the clutch stiffer as well. Maybe OEM parts are the way to go!