Scott Dinger and Randy Smith were the only two after market tube mufflers that I know of. They both can be spotty on availability and sell out fast when they are. Scotty has a busy weld shop but ping him regularly and he will get back to you. Like the Pickers say, the time to buy 'em is when you see 'em!!
For a stock muffler, the Tower .40 muffler is lighter than the stock OS unit. The E3030, 843, and one other all are the same size but differ in weight.
Type at you later,
Dan McEntee