I have a 92 with 5 spd. Would like to make a pillar mount for tach, EGT, Boost. Q is I read most tack hook ups is in steering col...on tilt wheel just remove the lower plastic cover and look for the 4 pin harness with nothin plugged in?

 

Here is som info on tachs:
Dodge Diesel - Diesel Truck Resource Forums - View Single Post - Questions about hooking up a Isspro tach
This is what I also used, Isspro. The factory plug is under the dash, mine was to the left of the steering column.
Let's Screw-Up Your Steering Column With A New Tachometer and Gear Shifter! - Dodge Diesel - Diesel Truck Resource Forums

 

Yeah all the 92's have the factory tach hook up.