The Dana 300 Billet Adapter/Flip Ring is 7/8" thick allowing you to mate and flip a Dana 300 to driver side front output onto Aisin flange style transmissions which include the 4wd versions of the AX15, AX5, and the AW4. To mate a Dana 300 to the 87-90 AW4 or the AX5 will require a 21sp Input for the Dana 300. All clocking rings are engraved with wide set location for ease of installation. Our clocking rings are precision CNC Machined for accurate bore alignment. The Flip Ring allows you to flip your Dana 300 to be used as a Driver Side Drop, with additional clocking positions.