My 2 into 1 HKS exhaust with tractor muffler was getting rusty. I substituted 2 piccolo tubes - same rate of climb, no noticeable change in noise, much easier maintenance, and 9 lb less weight. It makes the exhaust come out as a series of tiny barks instead of a few big ones. Holes face to the sides and aft, have a total area larger than the cross sectional area of the pipe. Finisned it with old fashioned black wood/coal stove polish.
Larry