Steering Knuckle & other part Identification

[gizmoduck81]

Hey everyone. Hoping someone can help me identify which parts the prior owner used on my 1963 GMC. The engine is out of a 1988 Suburban R20 (454) and I'm trying to figure out if the disc brakes and related parts are from the same vehicle or something else. I couldn't find any guides through search on how to identify these parts and looking up casting numbers hasn't really helped.

I'm specifically trying to identity the steering knuckle (spindle), upper ball joints, tie rod ends, and the crossmember (is it original?).

Brake info I know: Rotor is 11.86 x 1.25, 5 lug. Caliper is JB5

I have 71-72 c10 upper ball joints installed and they feel tight, but the cotter pin is above the castle nut, which obviously makes me nervous.

I ordered upper ball joints and tie rod ends for an '88 R20 and although the tie rod ends look right compared to what was installed (new above, old below in pic), the upper ball joints are different (old on left, new on right in pic).

Any help would be appreciated. Pics attached. Let me know if more info is needed and I'll provide when I can over the weekend.

Thanks in advance!