Sounds like your fighting the 0-30 ohm vs 0-90 ohm gremlin. GM used 0-30 ohm gauges from 1960 - 1966. 1967 and later use 0-90 ohm. The aftermarket uses 0-90 ohm and call them 'GM' style. A one third full or more tank with a 0-90 ohm sender will drive the factory gauge to full. Either replace the sender or put a 43 ohm resistor in parallel with the sender. Works pretty good. You can get the resistor at Radio Shack.
Jim
Last edited by Jim Gracey; 01/05/2008 5:29 PM. Reason: typo
