[jlsanborn]

I'm for sure no expert on forced induction but would think the metering principals of the carby are similar. That double pumper has "power valves" right? Those would be the equivalent to the "step up" springs the previous poster is referring to. In both cases they are rated in inches of mercury. In naturally aspirated engines that would be considered the pressure below atmospheric (vacuum) but its really the difference between the air horn pressure and intake pressure (differential or pressure drop).

Truck looks awesome and its cool you're getting to shake it down! Can't wait to see the bed on it.