I have a 1955 2nd series pickup with a 32 or 34 gallon gas tank located in the rear of the truck bed. The truck came with VDO gauges. The gas gauge registers half full when the truck is full of gas and goes down from that point. I can't tell when I'm getting empty and would like the gauge to show correctly. I'm thinking I'll have to get at the sending unit located on the tank. Is the best way to do that by removing the bed or trying to drop the tank? Any suggestions on the gauge? A BIG thanks for any help.