Hi all. I've read enough to know that on a very basic level, there is a degree of interchangeability between 1800 and 122 rear axles. I was hoping to get some insight into the details so I can ask the right questions. I found a seller that has a P1800 rear disc brake axle with a 4.10 rear ratio that he'd be willing to sell me for $150. (Is this a good price?)

My '67 122 currently has the stock rear drum setup and an M40, and since it was an automatic I think it has the same rear ratio (4.10). What should I ask him about the axle in order to determine if it'll fit? I'd like it to be a straight bolt-up if possible. I'm guessing if it's out of an ES it won't work. But is there anything else I need to know?

Lastly, he said the rotors might need to be turned. Are rear rotors as unobtanium as front 122 rotors? Should I walk away from a unit that has bad rotors?

Thanks!