Don's Muffler Service on 10th St. He's a jeeper (flat fender) and did custom work for my old CJ7 and my 89XJ.
Do NOT go to Discount Muffler on 11th, I use to work across the street & have seen to many cars on fire there from their careless torch work.
There's also a place on Harrison St, on the left side between 5th & 7th. It is an auto body or detail shop that sublets one outside hoist to an old guy whose entire inventory is in a shipping container, good fast work putting a cat into a vehicle when Don was closed up for vacation. The exhaust company sign is very small, blink and you'll miss it.
Tom