Ok so I am very ignorant when it comes to u joints. I can change them but when it comes to sizes I'm lost. I just put my 70u in my 1970 f250 and thought it was the same joint but it's not. From my best measurements on the yoke it needs one that is .07 larger in dia. The cross is the same length the cap dia is what is different. To make matters even more confusing for me the truck came equipped with bastard joints. I am completely lost and have no clue what to do to get it hooked up. I need some serious schooling.