RE: Tower Hobbies .46 Mufflers Question
In the .40-.52 size range engines, the OS, Tower, Magnum, Thunder Tiger, GMS, Tiger Shark, SK and probably others have the same muffler bolt spacing. Any muffler for any of these engines will fit any other engine. As has been mentioned, the Tower muffler does act as a tuned muffler, adding, in my experiments, 800-1200 rpm depending on prop. On 3D size props, 12.25-3.75, I got 800 rpm. if you change to an OS style muffler, expect to lose power.
Super Tigre, Webra do have this same spacing.