Thanks for all the help. What is the purpose of the PV and how does it operate? If manifold pressure drops to a certain point, will the PV open? The last time I checked my manifold pressure it was above 10 inches at idle. Don't know what it would be at WOT or part throttle.

My car 74 Duster mild 360/904/3.91 13.44/101.54 Son's car 75 Dart Sport 318/904/4.10 looking for a 360 or 408 2004 Dodge Ram 1500 Laramie 5.7 2010 Dodge Challenger R/T Classic B-5 6 speed 2010 Jeep SRT8 for the little wife