Has anyone had a XU-1 style muffler modified with larger inlets and outlets. Say 2.25" in, 2" out, but same body size as original? I don't need to worry about the muffler looking original, but I would prefer the thing to look similar. Or should I just get my 2.25 exhaust turned down to 2" and stick with a XU-1 repo? Some time ago, somebody mentioned that he thought these mufflers were restrictive. Are they really? Alternatives are only 14" long.