I have a '73 barracuda that I am rebuilding the front suspension on

My disc brake spindle has what looks like 4 3/8" mounting hole spacing. The new lower ball joint has what looks like 4" mounting hole spacing. And the hole
Size is smaller in the ball joint.

What's going on here? Can someone tell me what lower ball joint I need? Of course, i have no idea what parts have been put on this thing over 45 years.

Robby