B2600 4x4 Upper control arms

I was looking at the 4x4 upper arms I have from my old parts truck and is it just me or are they the same as the 2wd?I was planning on welding some 3/4" round steel into my 2wd arms and if these are the same I will just weld these up at work instead.I know the lowers are different but do the 4x4 uppers swap over?

Thanks

no they are completely different

Just wondering whats the purpose of welding the 3/4 round steel in there?

Was planning on cutting the cup in the center wider but there won't be enough strength there without re-enforcing it.I had air shock on the front about a year ago and the fitting was too close to the arm so I figure if I brace the arm with 3/4" round steel I could cut a notch out to clear the fitting.I was planning to use the leftover 4wd arms because the arms look identical to the 2wd ones on my truck.

The uppers are too?I know the lowers are.The uppers look like they use the same balljoint.

i just looked at my mazda shop manual, and they are different