Search by number: 1991 GMC Full Size Pickups 7.4L 8 Cyl Alternator ProAmp 7901-7 $61.00 each OPTIONS: RV3 Models - Option ProAmp 7802-3 $93.00 each OPTIONS: C K - w/AC Option 105 Amp ProAmp 7802-11 $113.00 each OPTIONS: RV3 Models - Standard ProAmpN 7802-11N $103.00 each OPTIONS: RV3 Models - Standard ProAmpN 7802-3N $123.00 each OPTIONS: C K - w/AC Option 105 Amp ProAmpN 7901-7N $145.00 each OPTIONS: RV3 Models - Option Why is there more than one unit for my car? Look at the TECH SPECS when more than one unit is shown for your car. AMPS (ELECTRIC CAPACITY): must match you vehicle electric requirements. *** Call us if you are looking to increase your unit capacity! OE ALTERNATOR MANUFACTURER: It is recommended to match the Make of your alternator