Search by number: 1999 Infiniti I30 3.0L Alternator ProAmp 13639 $137.00 each OPTIONS: Standard 110 Amp ProAmpN 13639N $159.00 each OPTIONS: Standard 110 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