(1 1/2") Longer Than normal Axle U Bolt 64-66 - 7/16-20 x 6 1/2" Extra Long U-Bolt 

These bolts are commonly used with lowering blocks to lower the vehicle by 1"

See part number -C5ZZ-5705-LK1  for lowering kit complete.

Bolts sold individually.

64-66 Mustang.

Part Number- MMB11707 

inside width is 57MM