Small Engines (Lawn Mowers, etc.): Exhaust on 11HP Briggs, stock muffler, old john deere

Question
Hi, I'm in the process of restoring an old John Deere 111 and I was wondering if changing the exhaust would damage or shorten the lifespan of the engine (B&S 252707 0228-01 81100711).  What I would like to do is remove the stock muffler and use a pipe of some sort with a flapper.  Simply because I think it would look and sound better. I would just like to know what your thoughts are on the subject, thanks.

Answer
LOL - well- it'll sure sound DIFFERENT (and a bit loud)

- find a supplier that carries thin-wall pipe with NPT threading on the end of the same size as your muffler).  You'll start with a piece about 18" long.  Run your engine for about 30 min.  Notice that the pipe has changed colors along a certain length of itself?  Cut it off just beyond the color change.  This is the minimum length you should go- if still too long, have someone bend it into a loop.  If possible, devise a bracket (small angle-iron from lowes works well) to clamp onto the end of the pipe and support it to the frame(prevents vibration from tearing the threads out of the block).