for years I flew mine on 4s 120,then to save fuel cost went to gas,I just cut the cheeks off,mounted the motor inverted,moved the fuel tank to c/g,after converting tank to gas. I fly mostly off grass so years back I beefed up the landing gear. the firewall has tri stock all around then pined with dowels,now flying with G38 which I like even better.I use a slimline muffler with smoke.