I have a grain truck with a 3208 Cat in it.  It currently has a straight pipe that is in need of replacing.  I was wondering what kind of horsepower loss, if any,  would be seen if I added a muffler to this truck.  Could put one in-line under the cab or try to find one that mounts to the side of the cab- Doen't really matter to me whatever would be easiest and work best.

Don't get me wrong it sounds cool. But as I am getting older my ability to hear is becoming more important than looking cool.

Thanks

Ryan