blwblw: have the .45 training engine and the .46NT. Both are super engines. The .45 is the best of the two. I'm not sure why you say the mufflers are a POS.
It might be related to the lemon I originally got that probably vibrated excessively, however, I went through 3 Evo mufflers that all vibrated loose and separated in flight. I even used a threaded bolt all the way through with two nuts on each end to get it to stay together. I never had this problem with the Tower muffler and also the RPMs went up considerably when I switched. There are other threads mentioning a similar problem with the muffler. POS might be excessive, but I'm much more happy with the Tower muffler....