This is a rear axle pulled from a 1971 Pontiac Grand Prix. It's a Chevrolet style 12 bolt 3.07 posi with the Pontiac XT code. The casting number is 3969278 with a axle stamping XT 0813K with a E under the XT (see pictures) Very nice gears and posi unit. Housing has surface rust with some minor pitting. This rear will bolt into any 68-72 GM A-body (Chevelle, El Camino, Monte Carlo, 442, Cutlass, GTO, Tempest, GS, Skylark)