Ours are stock except rotted resonators have been replaced with Thrush glasspacks. These engines are notorious for highway drone after exhaust mods. Try searching a bit and see if you can find a sound you can live with. Ironworker, eh? I'm in sprinkler fabrication, 1/2 welding shop, 1/2 machine shop. Just south of Boston, 600 miles EVERY week. SUX.