That's correct because workshop has you checking fuel pressure at the back of the heads on an E-van, but if you're checking at the secondary fuel filter like on an F-series, the proper pressure is still >= 45 psi at WOT.
I cannot emphasize using the supplied 6.0L Diesel Fuel Flow Tester (310-193) enough, it's so quick and easy to set up, and gives you accurate readings, and allows you to see WOT pressures without having to put a load on the engine!!