I have 69 SS clone that I bought already done and don't have access to the guy who built it. My driver side sway bar link is missing and I'm trying to ID the proper part as it's 1/2 the length of the factory one. Here's a pic of the passenger side link that is in place. Any thoughts on how to ID the proper link so I can buy the driver side replacement?

 

It seems like you suspension is lowered, and your sway bar is a lot larger than stock. Since it looks like the lower control are not in its stock position then stock sway bar links will not work.

I have always gotten adjustable sway bar links for lowered cars. This allows you to adjust a little preload into the sway bar. It looks to me that the past owner just cut down the sleeve on a stock sway bar link. You could buy to links of a stock 69 use the rubber from the new link on the passenger's side and on the drivers side cut the sleeve down to match the height of the passenger's sleeve.

NOTE if there are not enough threads there you may be able to run a die down the threads to make more, or you may need to go to a real hardware store and get some grade 8 bolts that are the right length so they can be tightened. This is the kind of fabrication you get into when you use non-stock parts.