Part of my thinking is that I can do the tricky bendy stuff in copper (I can solder but not braze) and stake the joints with a self tapping screw. After the bendy parts a 3" stack held in place with standoffs (they are hangers if it was horizontal).
I don't care how loud it is, I'm half deaf anyway and I live in the country and never start to do anything other than drink coffee before 10 A.M. IF I find it is too loud, I have a muffler that was destined for my Farmall but missed the sale.
The whole purpose of this is (a) to make the engine breath better and (b) to get rid of the grass burner exhaust.
(a) 4 stroke engine strokes= suck, squeeze, pop, fooey. injection, compression, ignition, exhaust. Stuff a potato in your exhaust pipe and see how far you get. Not far. I have always run on the premise that in order to get anywhere with an internal combustion engine you MUST get the exhaust (fooey) out!
(b) the grass burner exhaust turns the snow blower black (normally it is orange), turns my loader arms black and tries to plug up when I am pushing snow banks.