32 rear trans support/torque tube cap bolts

[36and63]

The 32 transmission support requires t-bolts to fasten the torque tube cap. I see that the support has the rubber cut out where these are but not sure what keeps the bolt from turning since you cannot hold them with a wrench and they are sort of L shaped. I need to purchase some so I'm just curious how these keep from turning when you tighten them.

Thanks,
Pat