So if your looking at a A-body upper control arm, sitting on a table at a swap meet, how can you tell if it is a LBJ or SBJ control arm? Is there a measurement across the flats of the ball joint to look for? WHat is it? Or is there another way? Thanks
The ball joint is bigger and the diameter is larger. Take an old SBJ control arm for comparison. The smaller ones are more prevalent, as the
big ones are usually 73 and up.