Digital Dash: Everything works except oil pressure, temp, etc. gauges.

Sounds like the dash power supply.

There are several guides and posts about howto resolder the pins for the connectors.

I've never had any long term luck doing this, so I eventually found a good working one.

Thank you! Will try doing this within the next week and see how it goes.

Did you ever try this out? Everything on my dash works, except the fuel gauge readout.

I did the power supply mod. Same issues as OP

I tried re-soldering the joint in the circuit board of the power supply unit and it did not fix my problem. A few weeks later my dash went completely out and replaced it with a re-manufactured one. My dash is working just as before minus the gauges so in my case it's not the power supply unit. I'm in touch with the person who sold me the power supply as he is more experienced; so, if I find a fix I'll make sure to post it on this thread.

every time I have had the right gauge set inop, it's been the cluster itself.

check the wiring harness connectors on the back of the cluster for corrosion

Same problem

Oil, temp, and voltage out. Who has a spare lying around they want to sell?