So, I have seen mentioned in a few different posts to mark the driveline on these newer units so you don't get them in wrong. When did this become a thing? I have been out of the garage scene since 2001 and haven't owned one of these newer than my '99, so I'm in the dark on this. I have never had an issue with just sliding the shaft in however it would go in. If it was required to go a certain way, there was a keyway in the output shaft that matched the splines on the yoke. If it's so important to line it up exact, why didn't they use the keyway set up?