I have FINALLY solved the problem; I hope!

Advice from a guy on another forum (if you look in here, Lewis Matkin Jr., thanks once again) is that you need to replace both the switch and the switch cup, that's the stamped metal housing, with the 63 Chevy item, as the bolt patterns differ.

Carrie at Classic Parts is on the case with this, so I hope to be fixed up soon! grin


63 GMC Fleetside; overbuilt, over-thirsty and over here!