I am converting over to 12 volts and have pretty much got all the problems worked out. Now for the gas gauge. Any ideas?

Call the Filling Station, Chevs of the 40s or some of our other fine suppliers of good parts, they have what you need. I guess it takes two resistors one for the sending unit and one on the guage.

My 1951 Chevy COE "slide-back" truck was converted to 12 volts back in the early 1960's and the gas gauge never had an inline resistor installed and the gauge has worked fine all of these years. When I got the truck back in the mid-1990's, I didn't want to take any chances so I installed one inline resistor that I purchased at the Filling Station. The gas gauge is still working the same like it never cared about the situation either way!

Skip is right, as he is once in a while, the main thing is to reduce the input voltage to a nominal 6vdc. Please look on the schematic diagram of the vehicle in the vehicle's shop manual ( if you don't have one order one when you talk to the folks at The Filling Station), be sure they know you want a dropping resistor for a 6 v fuel gage. Just be sure the resistor goes in series between the ignition switch and the gage.