there was a guy i went to high school with and he did the spark plug thing to his exhaust and richened up the carb so it would blow nice sized flames, well to make it short and simple when he hit the the first time it whot a flame and then when he let off the throttle the flame went bak through the exhaust and into the block and did hella damage.......i would not recommend the ghetto engineering way of getting flameing tailpipes.