[asshanson]

Had to get some 3" clamps like this for the Vette when I put in a Z06 exhaust, went to napa and they were under $10 each. Worked perfect.

Or I have two of those clamps pictured in 2.5" but the bolts should work for 3" if you want to reuse what you have. Free, I'll give them to someone on the cruise so you don't have to pay for shipping even.