Sonnax Mustang flanged yokes are for the builders of Mustang driveshafts who want to upgrade from a 1330 U-joint. Those builders have long had to make due with purchasing an extra adapter flange to allow installation of a 1350 flange yoke. Now, with Sonnax flange yokes, the days of sourcing an extra adapter are over. Sonnax yokes are forged and precision-machined to accept a 1350 U-joint while maintaining compatibility with the OE 3.5 in. bolt circle.