I'm getting ready to finish a top flite 190 and have a tower hobbies .75 engine for it. Anyways, I'm having a hard time deciding what the best way to install this engine would be. Should I go 90 degrees and run with the stock pipe for power output or run a bisson pitts muffler? Or, should I run it inverted with the top flite in-cowl muffler. I'm concerned about power and reliability so I'm really tempted to run with the stock muffler. Can anyone give me an idea on the reliability and power loss effects of the top flite in cowl muffler.