Working on electronic ignition conversion for HP273 dual point distributors

66fs said
There you go. Original caps were black without a vent. Contacts were brass, I'll second using dielectric grease on the plug wire sockets, not sure I'd use it anywhere else.

Yes.
I have a ton of 273 photos but I don't see any with enough clarity to see the cap. Most have black, a few tan, one or two with red, and of course a totally incorrect blue. LOL I bet @65dartcharger will agree that the black is correct.