Shock options for 85-86

I know this topic has been posted on here many times but it seems like I keep coming up with the same answer, nada. I can't really afford a nice set of works right now so I am looking to find a alternative oem shock for the rear, the rear I have now is way to soft and leaking and doesn't look like a good candidate for rebuilding. I've looked at a couple buddies quads and on ebay for cheap shocks that look like they might fit. I figure if I could get a used rear for $50 or so I would be doing all right and if it doesn't fit, oh well. I'm not sure the length of any of these shocks but it looks like maybe(big maybe) A predator 500 Fox might work, saw one with a Buy It Now for $65 shipped. Anyone know where I could find out the length of this and other shocks? The stocker is something like 15" correct?? Also a buddies raptor 660 with remote rezzy looks like it might fit although it seems a little long. Anyone tried anything other than the z400 on the newer lt's??