That's a balljoint 60, not a kingpin. Also, blocks in the front suspension are a no-no. I haven't seen a van setup with the shackles at the front of the front springs in a long time, looks like stock F350 (<'98) design.
Also mounting leafs to the front of the crumple zone is a huge no-no as well, unless it’s reinforced. That van was most likely a home build, and it probably was not really drivable
The J is correct ball joint, not king pin. Blocks big no no. Shackle forward and the crash frame horns yikes. Shacles forward worst ride quality you can have.. Definitely good start just fix the mistakes it will be fine. I'd just go 4 link with 3.0 coil overs and use the rear fixed mounts as my lower arm mounts they look very well mounted.