66 Dart GT HT Whatsitgonnabe?

I have another project you might want to do to your gages as well. The stock gage cluster oil press gage, water temp, and oil pressure gage (if equipped) all run off of 5 volts. The printed circuit card on the back of the gage cluster should have a small mechanical vibrating points type voltage regulator. On my barracuda it was located inside the gas gage. Anyway the problem with these, is when they fail open the gage needles drop to the low position, when they fail closed the gage needles peg full high position.

Its a simple device you can make with an NTE960 semiconductor, and a small microfarad capacitor. I cant remember the number i used. However one leg on the semiconductor is ground, one leg is 5V output, the other leg is your input from the 12V feed to the instrument cluster. This replaces the mechanical points regulator.

I used ring terminals and piggy backed mine off the studs on the circuit board since mine was originally inside the fuel gage. If yours uses spades pushed into a dedicated spot on your circuit board id recommend tapping the solid state one right back into the board. I have seen it where guys mod the original points regulator housing and fit the solid state semiconductor inside.

As an electronics engineer this should be a piece of cake for you to do.