insane4fbodys I have just got back home to check my pulley size an its 4 1/2" o.d but it is only a 46 tooth. You may want to just go with the smaller pulley to fix your problem and just not turn your engine so high to keep the boost down. Also Jeff is right about the pump for the 1/4 mile and I have mine turned up all the way. My biggest problem now is that my floats keep hanging open but as soon as Steve Morris get his new bowls made that will not be a problem any more. They will hold a lot more fuel as you can see on his web site. I have to change out from the reg that I have now to a 13202 Aeromotive reg and that will fix another problem that I have. Well the only thing that I can say for sure is that stop worrying about saving money.