Archie wrote:

I was wondering if anyone there would know what this plug is for? It's on a 78' Macho, 360 4spd. It's comes out of the engine harness over by the temp. sending unit. Thanks a bunch, Archie

looks to me like the dist plug, and in the right spot for a big block engine....

Thank You --- guess that would explain why it was never used. I now have aftermarket electronic dist. that has it's own plug.