The DRAC up to '91 is inside of the cluster and not a separate unit.
If all of the gauges have issues, then there is probably one problem, not several. Could be the ground. I hate my half-moon gauges too.
The TBI distributors are still considered HEI. If you want more spark, make sure the distributor is in good condition (good cap, rotor, and make sure the pickup coil isn't falling apart), then buy a better coil from one of the aftermarket companies. Also check your timing with the timing connector disconnected.