You are correct, the driveline out of my 69 Camaro, had smaller u-joints than my 68 Bird, and it has a 12 bolt posi 4speed ,but all 3 drive lines were out of phase, my 68 Bird, the 69 Camaro, and my son's 68 Camaro, I still need to pull the drive line on the 68 Camaro, and see how the slip yolk on it looks. The show was in Coeur d'Alene Idaho, they do a classic car parade on Friday night and a car show on Saturday, it was pretty cool, about 1200 cars, the parade was rough on the old cars too slow moving, still was a great time though.