Installation Notes: This unit comes equipped with a smaller 1.75 inch diameter alternator pulley, and will require a slightly shorter drive belt for proper belt tension. Not recommended for sustained use above 5,000 RPM engine speed. ((Check instructions section for finding belt sizes and wiring)). If you DO NOT use the correct shorter belt, this will result in very low to no output and create extra work load for the alternator. The Elite series offers the highest possible amperage and durability available in a large case alternator. 6 phase technology combined with massive twin rectifier assemblies and 12 diodes makes these alternators totally durable for daily use, while still maintaining 200+ amps at engine idle speeds. These alternators use the more robust 4 pin style regulator than the OE 2 pin ECU controlled alternator. There is no extreme voltage fluctuation as this will bypass the RVC charging system on all 2005> GM truck applications. Simply install the included 1 wire P101 harness to a tested 12v switched source and plug in the included P103 module into the vehicles 2 pin original alternator wiring harness. No check battery light, no computer controlled voltage swings. The voltage you want, when you want it!