Tuff Stuff 7139ABUL6G12 GM 100 Amp Alternator, Chrome

The Tuff Stuff 7139ABUL6G12 is a chrome-plated, 100-amp alternator wired for OEM or 1-wire hookup, cataloged under Tuff Stuff's General Motors and 1-wire lines on the 10SI-style case.

Fitment to confirm

This part number's coverage starts in 1982 and runs through the 1990 model year, taking in Buick, Chevrolet, GMC, Oldsmobile and Pontiac on the GM side, with Jeep and American Motors vehicles sharing the same case design. That spans both V6 and V8 GM engines, plus the L4 and L6 Jeep and AMC engines built on this case. Since coverage shifts from one model year to the next, double-check your specific year, make, model and engine fit ahead of ordering.

Mounting

Pulley is 6-groove, case depth runs 4.85 in., the lower mount boss measures 2 in., and clocking is set to 12 o'clock, so check that orientation against your accessory bracket. This one is wired for a 12-volt, negative-ground electrical system.

Condition

Built from 100% new parts and backed by a one-year limited warranty, this unit suits a straightforward like-for-like replacement rather than a used, pulled-from-a-donor-vehicle alternator.