When I ordered the cat from Walker, it came with the gasket despite the description not mentioning it. Some sort of pressed fiber material as I recall. I ended up cutting the bolts using a cutoff wheel. You can knock them out of the bracket and replace them with regular bolts. For clamps, do yourself a favor and order the wide "megaclamp" band-style clamps instead of the cheap u-bolts. Much easier to install, seal better, and you can loosen them to readjust if needed because they don't crimp the pipes. Once you tighten the u-bolt style it ain't coming apart again.
