Pulled off the old tach cable, it was snapped internally so I put on the new one and the tach in the dash jumped around from 2-3k while at idle. I found the replacement in a box, popped it on, and it works perfectly. So nice to have all of these parts.
BTW, anyone know where to get the little metal fins that are used to replace bumpers, say like in the picture of the cobra below? Not sure what they are called so can't google it