what gauge ? tach? fuel? temp? vaccume?
since you said tank ill assume fuel. autometer gauges are calibrated for 240 ohm empty, 33 ohm full. if i remember corectly toy's are 90 ohm empty-0 ohm full, wich is just the oposite of a gm calibration (0full, 90 empty). so if you got the gauge calibrated for a gm sender you'd just have to remember that it would read backwards.
