69chevyman, for the st. you dont wont but 5- 6 lbs. of pressuer at the carb. driving down the road, so at WOT its gonna drop some, so get the right size lines on the car, strighter the fuel lines the better, and if it stays around 4 lbs. at WOT that will work fine. the least amount of fuel pressure (at idle that you can live with) the better off you are.