I went out and looked at my '33 to refresh my memory. Bottom links are parallel, mounted to the diff tubes at the frame width. The top links are mounted to the diff center section, just inboard from the tube to center section joint. If you project a line through the diff mounts on the vehicle center line the links point outboard at nominal 25 degrees, which says that from the diff the angle is nominal 65 degrees. If you bought a 4-link setup specific for your chassis the length of the links determines the mounting angle, and the angle is not really important, just that it's triangulated.