This appears to be the oversized lower ball joint that Carquest shows since that's where you posted the last part coming from. I'd double check though just to be sure. It wouldn't let me punch in anything older than 1975, so I used 75 c-10 chevy 5.7l as the reference. #505-1021OS (oversized)
http://www.carquest.com/webapp/wcs/s...8682?acesApp=1
I also use Red Locktite on my lower ball joints. I've never tacked a set in personally, but have heard a lot of people who have and have seen quite a few done that way.