I use Max wedge style threaded ball adjusters and nuts, They are 5/16 24 thread . I see one in your picture with a screw driver slot. big block cranes are 3/8 24. All cranes are allen head style. also used hardened jam nuts.
Thank you, so are the threads of the ball head screw you show from Crane a standard 5/16x24 with no interference? Just the nut that has the interference thread?