Bill,
I don't understand how your 235 can be quieter with no muffler?
A friend of mine has a 261 in a truck he uses around the farm. The muffler rusted away and now it is just has the pipe going to where the muffler was, the truck is quite loud even when just puttering around the farm.
I had the exhaust system replaced on my 52 with a 235. It had a muffler on it to start with, and original looking one, but was probably a replacement.
The new exhaust was the same, with a similar looking generic muffler.
The new muffler made the truck much nicer to drive, as it was quieter and you could actually hold a conversation while driving. And I did not think the old one was bad till after I had it replaced.
Grigg