hmmm, so it'd appear the senders aren't correct or you've used teflon or other sealer on the sender threads, isolating them from the required ground - if you ground the oil pressure sender connection, the gauge should read above 100psi .... not sure about the computer hookup, but the gauges should have their own senders, are the senders from ,or recommended by, Classic Instruments? are you using the Classic Instruments wiring harness?
as said, the senders are simple variable resistors, they don't generate signals, they respond with resistance changes to temperature or pressure changes
Bill
