Okay, I'm really liking my .40, but I'd like to try a standard muffler, so I can easily install the engine in different planes. The Morris site lists a #3245 for "trainers". I did a search and found out that there are two types, 3245 and 3245a. The "a" is quiet and apparently robs the engine of a lot of power. The morris site didn't list any "a" variant, just 3245. Is there a big drop in power with this muffler compared to the mini tuned 3248 silencer?