Hey guys, I have been giving this some thought...
I think maybe the clamps are having a hard time clamping down around the stainless because the clamp is too far up on the pipe. It is very hard, if not impossible for the clamp to tighten down if it is not over the slotted part of the tube. The slots are 1" long, the clamp is 1 1/4" wide, therefor if you slide the clamp all the way up the tube you are essentially trying to clamp 1/4" of round un-slotted tube along with the 1" of slotted part. I think the clamp is having a hard time doing this and in overworking the clamp it may be stretching the band, or the bolt, or whatever.
Please see the following pictures, if you slide the factory tube into the muffler tube all the way (or at least past the slots) Then put the clamp on the black line it will probably work just fine, putting the clamp to the red line would be the problem area.
What do you guys think about that solution? I tried it here at the shop and it seemed to make a real difference. I am happy to send new clamps to anyone who needs them.
Matt