You can buy a stock style muffler. Take some photos to an exhaust shop, that is what I did on the 53.
Exhaust I bought mine off EBay at: classicexhaust@windstream.net for $170, aluminized and COMPLETE. Great quality, delivery and fit! Bolted right up.
Exhaust I got a stock-style complete exhaust system from Kepich Exhaust in Florida. It was cheap and fit perfectly. Be very specific as to what engine you are using as the engine pipes are different for 216 and 235. I was very satisfied with their product. Their phone number is (800) 365-5764. I bought it in 2006 for $175.00 shipped to my door. Hopefully, they are still in business. Andy
I had a shop do mine. But mine was cobbled up right out of the manifold, so he fixed all that. Plus ran a split right after the rear axle for 'dual' exhaust with the pencil tips. I just have straight pipes. People can't believe it, as its not very loud at all. I may go back with a muffler someday. Anyway this shop was like 180 bucks or so. Another guy quoted me 600. So it pays to shop around