OK, calling it a muffler is pushing the truth, amplifier would be a better description. There are no baffles in these exhaust, this is how they were back in 1962 or whatever, just straight through pipes that produce an ear splitting exhaust note, it really has to be heard to be believed. Anyway, I had watched a video of Allen Millyard being a genius making the similar exhausts for his RC166 replica, he made it look so easy. Except it really isn't easy, it was an absolute bastard of a job. It may have been better to have done it in less than 35 degree heat but the fact is bending a steel sheet of that size requires a surprising amount of force and you have to do it without denting or scraping the metal, it's an absolute pig. I have to confess to not being 100 per cent happy with it but without having proper rollers to form the metal I have done my best with it. If I ever find some better ones I will replace them.