GMC Repair: Gas Gauge troubles, o reilly auto parts, o reilly auto

Question
I recently bought a 1996 GMC sierra 1500 with a 5.7L Vortec. Rebuilt engine and tranny, many parts put on it. My main question is about my fuel gauge, it tends to not read at all, it knocks back and forth, it will even loop around and hit the needle below it on oil pressure. What could be the cause of this and how can i fix it without being to pricey

Answer
I would go to autozone or o'reilly auto parts and have them scan it, or pick up a cheap scanner for yourself, and see what comes up. You will need to replace the gauge cluster. Unfortunately, you cannot replace a single gauge. I would go to a salvage or a pull a part yard.