At only 7,200 rpm. you really aren't getting into where a finely tuned header will make that much difference. I would build a nice set of 2-1/4 to 2-1/2 step. You could even do like funny car double wall to keep the heat out of the car. You can make 240mph with a 2.95 rear ratio, (tranny 1.00 I presume) 33" tire, according to Wallace. Doesn't the car weigh more than 4,000 lbs.? At your level of play, drag coefficient is really where it's at. More hp on the salt will create more tire spin if it's fighting a brick wall.