Search by number: 1957 Ford Ranchero 4.8L 8 Cyl Alternator ProAmp 5840 $105.00 each OPTIONS: Optional 40 Amp ProAmp 5838 $107.00 each OPTIONS: Standard 30 Amp 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