I use a JD2 bender to bend my tubing. The header in the pic is .049 6061 aluminum 7/8 dia. The muffler is 3" dia and 12" long. Im going to try some smaller mufflers with less baffling and see how far I can go before it gets to loud.

Zagnut; Your stuff sounds good if the material is any good. There are a few alloys of aluminum that cannot be welded or dont hold up very well to heat or vibration.
But if I had it I sure would try it too. Its hard to beat free
Adam