Made up this silencer for my 4 cyl, built up oversize the cast iron ends and used them as patterns to cast new end pieces in bronze, the body is stainless tube, through bolts stainless bar, nuts at each end. Instead of fitting baffles, I have the tail pipe extending into the silencer interior about half the length of the silencer, with the end plugged and small holes, perhaps 3/16" drilled around the pipe diameter, enough to equal the pipe section area. You can experiment with more or less holes if you wish, as this has some effect on the mixture. Your on SU's, remember the jet adjustment is for slow running only, changing the mixture on throttle open requires new needles to a different taper. I have a nice "ring" to the exhaust note and its not to loud.