The joke is on the guys at the FLAPS! The gauge Cosmo is referring to is simply an aftermarket mechanical gauge- - - -I'll bet they have one right on the shelf! Just disconnect the line going to the dash from the T fitting on the side of the block, plumb in a new gauge line temporarily, duct tape the gauge to the windshield wiper, and go for a test drive. Then check to see if the pressure reading is the same with the new gauge!
Jerry