I have an aftermarket 4 into 2 exhaust on my 74 CB750. The mufflers are too rusted to pass the safety. They are the type that have the 2 into 1 collector as part of the muffler, and they slip on to the header pipes. I am having trouble finding a replacement in my area that won't cost me an arm and a leg. Is there a 2 into 1 collector available that would allow me to use universal slip-on mufflers? I have been scouring the internet, but so far I have not found one that is purpose built for my bike. Has anyone used one that is intended for something else that has worked?