That's a Superchief, Brad. It's one of the most fun machines made, and the fastest production amphibious six-wheeled vehicle to date (some will argue that point). To be honest, the Chaparral charging system isn't very good even when it's working right. The most common problem is the rectifier/regulator, and they can be found from internet and mail-order sources. As far as the muffler goes, Attex offered a high-mount exhaust that came out the left rear top of the engine cover. I have one out and I'll try to get a picture of it posted.
Good luck with the machine; it's got some real potential!
Don
Stuck in the seventies- not in the swamp.
(6) Attex, a Hustler, a Super Swamp Fox, (2) Tricarts, (3) Tri-sports, a Sno-co trike, 3 Dunecycles, and a Starcraft! ...so far