F250/F350/F450 are all the same except for a few differences. The Dodge D60's, Dynatrac, Rock Crusher, the Fords, basically all ball joint D60's and straight axle D50's use the same ball joints.
The only difference between the 250/350 and the 450 knuckles are the caliper mounts. If you look at a pic of the currie setup you can see an aluminum bar that goes between the caliper mounts that makes it easy to mount a Willwood caliper. That can't be done with the 250/350 knuckle. So if you want to run 15" wheels you are on your own if you have the 250/350 knuckle and can use the currie mounts and willwoods if you have the 450 knuckles.