I've never worked with exhaust before so there may be a super simple answer here but the exhaust on my 75 CL360 is 1.5" outside diameter. The mufflers that I bought have an inside diameter of 1.5". When I slip the mufflers on they are very loose. I've broken 4 bolts tightening down the 1.5" clamp but they still won't tighten up to the exhaust.