parklamp ground and axle locking pawl
If it's what I think you're talking about it is secured to one of the RH axle nuts after you've adjusted the end play on the axle if you're using the tapered axle bearings. Some disc conversions use green bearings so the adjuster lock is not used. My disc conversion uses it and is assembled so can't get you a pic. Regular drum brakes 8.75 rear ends with tapered bearing all use the lock so someone is surely able to get a pic for you.