Search by number: 1985 GMC P Series Trucks 5.7L 8 Cyl Alternator ProAmp 7127-3 $98.00 each OPTIONS: Standard 63 Amps; 1 Groove Pulley ProAmp 7273-3 $99.00 each OPTIONS: 66 Amp ProAmp 7135M $116.00 each OPTIONS: Optional HD ProAmp 7127HO110 $254.00 each OPTIONS: Custom Built; 110 Amps; 15.1V; Replaces stock alternator with stock wiring ProAmp 7127HO110PFC $333.00 each OPTIONS: Custom Built; 110 Amps; 15.1V; 1 Groove billet pulley & fan ProAmpN 7127-3N $117.00 each OPTIONS: Standard 63 Amps; 1 Groove Pulley 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