I have a J-plate valver with a williams engine. I have a shake off my front passenger side which I have attributed to the driveshaft being worn at the box side. I can see it shaking up and down a bit.Question, can i buy the joint thing on the end without buying the whole shaft?Secondly, when I called the guy, he said there were two lengths 602 & 618. Which one is mine likely to have without having to pull it out and walk the mile to the motor factors. lol