Bolt, 7/16-14 x 1-1/4 hex HD for Velvet Drive 72 series transmissions, part number 4853E.
See our 72C Series page for more.
Item V12 on the Velvet Drive 1004 and 1005 V-drive parts diagram (Fig 12 V-drive gearbox). 8 per transmission.
See it on the parts diagram