ORIGINAL: nrthwing

First, I thought I saw a post where someone ran their exhaust down through the wing to the bottom. Is that possible and how is it accomplished? Does anyone make a muffler for pushers?
I hate all the goo that assocoated with glow and I'm sure this plane gets coated with the exhaust blowing forward into the wind.

Second, I see a lot of guys using the Tower 75 engine. Would the AX 75 produce more power? Would it be worth the extra $$$

Thanks,
mike