I have a 2 1/4" on my 46 2 ton from the manifold. It is stainless mandrel bent tubing that I ordered to make an exhaust for one of my Porsche's but felt like the truck needed it sooner! I think it's a little overkill for the original non pressure 235, but I had it in the shop and was a project I could complete without waiting on any parts.
The muffler is a Dynopack or something like that. I wanted to all be stainless so I didn't have to remake it. All the parts were purchased off of eBay from a seller called performance curve I think.
You probably won't find a shop to make a stainless mandrel bent exhaust for your truck. I would suggest going with a minimum of 1 3/4", but a 2" would be nice.
My .02 worth.
