High Output 250 Amp Alternator 14-19 GM Silverado Tahoe Suburban Escalade SierraNEW! The cast housing Elite series alternator 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 great output: 180 amps at engine idle speeds and a full 250 at cruising speeds. This unit comes with an OEM diameter pulley, making it perfect for high RPM and