what driveshaft?

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

I'd go with the 618, I'd say the 602 is a standard 1.2 and the 618 a Valver, you can't buy Williams shafts which would be another 19mm on top of that or there about.

Thanks mate. I've spare valver shafts.I'm going to take one down for it this w.e.