A friends Max wedge stick shift stock eliminator car went 10.50's with only 3/8 lines and a Holley blue pump. Why would you have 1/2 inch outlet and only 3/8 inlet? Depending on how hard your car leaves it is fighting that head pressure. Any fuel pump with an adjustable out put pressure of about 18 psi will work make your inlet at least 1/2. regulate the pressure at the carbs to no more than 6 psi. On my Stock eliminator car I have #10 inlet and #8 outlet pump regulated to 20psi with bypass and 3 psi at 6 pack carbs with 3/8 lines. Volume is more important than pressure. I run an Aeromotive pump.