well, i'm not caring if i get a pink slip or not [i'm retired], but just how many transmission assemblies [clutch, pressure plate, bellhousings] were dialed in to be true at the original assembly plant ? now you are correct the parts in question need to be inspected for cracks, burrs on mounting surfaces, bolt torque, etc. but over the years i have ran into problems with clutch discs and flywheel/pressure plate chattering. in all but a couple instances, the only way the problem was fixed was replacement of clutch parts. no dial-in of the bell was done. i am very well aware of the importance of the dial in process and the need for parallelism of the mounting surfaces, but there are more cars out there running just fine without those checks being done than those that have. when replacing parts these days however, care must be taken to insure there are no burrs on mating surfaces, and things such as pressure plate fingers are even heights and throwout bearing flanges are not dinked up. aftermarket bells need special attention. back in my day, however, replacement parts were of better quality than those available today. the OP asked for advice and all i could give is what i have ran into in over 50+ years of playing with these things. i make no claims about me being the only "super genius" in the land and a person should not listen to anyone else's experiences or expertise. you have valid points, and one could and should check these things. but to have us all "fired" because we state our life experiences is just a little course. it just kinda rubbed me the wrong way. i apologize if i have offended you.