I have a 2 bolt Y pipe. The Y pip didn't break. The end of it where I connects to the cat, basically 1 side of the cast iron broke off. So now only 1 side has a bolt, the other has a semicircle where the bolt WAS.

I got a new seal, the problem is obviously one side doesn't have a place to put a bolt. Which is why I was going to connect the cat and then try some sort of U shaped clamp to then bolt on, I was just concerned it wouldn't "give" enough for bumps and such.

Imagine a 2 bolt connector, but with one side half broken off(semi-circle), thats what I have.