Hi, if you want to keep the stock exhaust on the muscle then our widetire kit will not work. The 280 kit would use the same swingarm that the 300 uses so that would still be a problem for you. In order to run a 280 or 300 tire you would have to change the exhaust with our kits. If you change your exhaust over to a rightside only then our 300 kits will work. Let me know if you have any other questions.
Thanks, Rob at Hogpro