CPEX: I am confused about power valves too, but I have a very healthy street motor. I have a QF 950 with primary 78 & 3.5 PV. Can't remember secondary set up. Anyways, I want the motor to be a little better for street, because I will go to the track one or twice a year. The motor was in the car when i bought it & it is pretty healty... the trouble is, I just want a little better low end performance/ better idle w/ less loading. Do you think a vacumn advance would help? I don't have one now... its all MSD & 6AL. Would you mind telling me about low end efficentcey? Its ported & polished, 10.2 comp, Team G, BBC all roller w/ solid lift Lunatti. It has 3500 Stall & 488's. Any feed back appreciated. BTW- I drive it on the street occasionally as a toy only.