G Series 270 amp Alternator for 3.5 Nissan / InfinityG Series Based on late model 6 phase technology, these tried and true Nissan alternators are our best sellers. Reasonably priced and very durable, these units feature 16 heavy duty diodes in a a radial heat sink for excellent durability Installation Notes: This unit comes equipped with a smaller 1. 75 inch diamter alternator pulley, and will require a slightly shorter drive belt for proper belt tension.