Search by number: 1957 GMC Full Size Pickups 4.4L 6 Cyl Alternator ProAmp 10240 $118.00 each OPTIONS: w/Short Generator 6-1/8 Mtg Distance ProAmp 9005 $161.00 each OPTIONS: w/Long Body Generator 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