Upper ball joints

So I bought new project car. 69 Dart. It has a 360 W/spool mounts and disc brakes up front, which makes me think it is from a 73 and newer donor car. It has been sitting for 20+ years, as I was told, and the gas smells like it.
Anyway, the front end needs rebuilding. How can I tell what style suspension I have on the car. With the upper ball joints on the disc brake spindles, do I need large or small joints? I cant tell other than they are trashed.
With the idler and pitman they come from the underside and bolt to the top. My 68, was the other way. I need to order suspension parts, just unsure how to order them.
Thanks!