Need 7/8-18 Jam Nuts

[Motorman]

GM/Chevy pns are 14024806RH and 14024805LH.

Anyone have a local source for these? I need a pair of LHs

Local Chevy dealer parts man doesn't even know what I am talking about.

 

[GubNi]

I bought the tap to tap the tube for the TRE. I then got some hex stock and drilled and tapped it to make my own jamb nuts.