need help from gage guru's please

After alot of reading on this site about electrical/gage/dash problems, I decided to do some work on my car.
The car-'67 barracuda with dealer added a/c, 273 4v engine, complete fuel system replaced 10 yrs. ago (gas tank w/sump, electric pump, chrysler sending unit, all fuel lines, regulator, filters, & carb).
The problem-temp gage had stopped working a little while back, and the gas gage hasn't been accurate since I bought the car, and thus replacing the complete fuel system 10 yrs. ago.
After removing the dash, I found numerous loose connections on the back of the printed circut board. Tightened up all loose connectors, replaced all dash bulbs w/new bulbs, and re-installed dash. The temp gage works now, but the gas gage still is inaccurate. It shows empty after using about 7-8 gallons of gas. Has anyone got any ideas what could be the culprit on this one?