well whoever told you that is an idiot,,,think about it,,,the only way you would lose power from a longer swinger is the added weight,,,and if every 3"s of swinger is gonna make you lose 5 hp from extra weight is total bullshit,anyways, most aftermarket swingers arent that much heavier than stock,,prolly lighter. so according to your buddy,,,you are losing 60 hp,,,,,,lmfao. if your running a +12 swinger,,, i hope you have a bad ass motor to go with it because that is massively long man......