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Authenticity reference

Rear axle tag

numbers matching · documented

1971 Ford Boss 351 rear three-quarter view; reviewed for rear trim and graphics context. 1971 Ford Mustang Boss 351

Reference Details

Common issue
Open differential or alternate axle ratio installed during restoration
Confidence
documented
Correct value
3L91 indicating 3.91 ratio with Traction-Lok
Where to check
Tag attached to front differential cover, per Hemmings buyer guide

Cars With This Authenticity Marker

1 linked car page.

Sources & Documentation