OK, let me tell my South Bend clutch story. After installing the DD2's and slipping the stock clutch, I ordered a Con OFE from SBC and had it installed per South Bend's instructions by a local shop that's close to my home. When I picked up the truck, the clutch worked fine, but I had a pronounced first order vibration (i. e. , at engine RPM) that wasn't there before. You could sit in the truck at idle and feel the seat and floorboards shake!
I called Peter who assured me that all of the components of the OFE are carefully balanced, as I would have expected. I then asked my local shop to get in touch with Peter and work together to get the problem fixed. According to my local shop, Peter agreed to pay for corrective repairs if the problem turned out to be his - fair enough.
After tearing it down, the local shop found out that the machine shop that ground the flywheel had screwed up, and the flywheel had 0. 047" runout on the face. Even though they didn't perform the machine work, the local shop had sent the flywheel out to a shop of their choice for the work to be done, and obviously they had not put a dial indicator on the flywheel before assembling everything the first time, so they stood good for the repairs.
My point - unfortunately, stuff happens. When it does, all one can hope for is that he is dealing with upstanding, reputable business people who will fulfill their responsibilities to make it right. In my case, I feel that both SBC and my local shop did all that I could reasonably expect of them. That makes me a satisfied customer.
Rusty