Alternator, Powermaster, 1954-88 GM, CS121, 100A, 6-rib Pulley

GM CS121 100-Amp Alternator (6-Rib) by Powermaster®

A 5-by-5-inch case and side output post provide clearance without sacrificing 60-amp idle output.

The Powermaster® CS121 fits a compact 5-by-5-inch space, with a side-mounted battery-output post to help route the charge cable away from tight rear clearances. Its 60-amp idle rating helps supply ignition and electrical loads at low engine speeds, with rated output increasing to 100 amps at top end. The six-rib serpentine pulley is included; its 6.14-inch straight mounting span must match the brackets. The internal regulator controls charging for a 12-volt system. One-wire charging simplifies the output connection. Each alternator is individually dyno-tested. This compact race alternator is for racing use only.

• GM CS121 compact race-alternator applications • Output: 60 amps at idle, 90 at cruise and 100 at top end • 5-by-5-inch housing; 6.14-inch straight mounting span • Side-mounted battery-output post helps with cable clearance • Included six-rib serpentine pulley • Internal regulator with one-wire charging connection • 12-volt electrical-system operation • Finish choices: black, polished, natural • Individually dyno-tested; for racing use only