A couple more tips that may aid others to clear similar hurdles.
In the hope of completely eliminating the elevated coolant temps I was enduring during the Vegas summer, I had:
- Installed 11-blade fan & Hayden clutch
- Flushed and filled with CAT-spec NOAT coolant
Those measures only gave nominal improvement.
However, during this major surgery I have installed:
- New H2O pump
- Thermo
The only remaining suspect component was the lower radiator hose (radiator looks exc.), more specifically the turn at one end lacked an internal spring to resist collapse during coolant pressure variation.
Both rad hoses look otherwise fine; I have no idea if the OEM lower hose normally lacks a spring at one end, but I'm not interested in leaving it to chance. So:
OEM lower rad hose-end with spring;

Same hose, other end, no internal spring to my thumb:

New $5 shorty rad hose, unknown vehicle application, with corresponding segment of internal spring rotated-out:

Spring-segment clipped and transplanted into CRD-hose:

Maybe others have done this before, me no; I'm grateful to the Ensenada Azone staff for advising this solution.
I remain curious if that "empty" segment is CRD factory spec.
Now, this beast better #@%& maintain normal operating temps!
Another issue was that the left-side's JBA UCA bushings had been damaged during removal-from-hell (6-frozen lca/uca bolts, 24 hours labor). I never got a respone to my pertinent email inquiry from JBA, but now maybe I know why: they do, in fact, accept the OEM UCA bushings, Part #BCK96036 (@ azone).
Also, the JBA-compatible replacement upper ball-joint is spec for a '96 GMC 1500 Van, Part #B6292. This is clearly sub spicer-grade ($60 @ JBA) but for $16 seems adequate:

A local suspension shop's hydraulic press failed to coax-out the old JBA bushings, so it took the boss 2.5 hours to torch the old ones out. He'd quoted me $5 to R&R the JBA's bushings, but clearly he did not grasp what a pita these rusty #@&% bolts would be to remove. I gave him $10; he was both grateful and gracious.
Also, the JBA factory red paint was beat-up so I wheeled it clean and painted it silver. That's probably sacrilege... oh well.
Pic with new ball-joint/bushings:

With the left-front 1/2 shaft out I decided to replace it's diff-output seal ($10). Unsure if the opposing right-side seal is identical (located at the end of the right-front's elongated axle-tube).
FRONT-LEFT DIFF OUTPUT SEAL DIMENSIONS: 58x35x11mm; 35mm is the approximate ID of the seal's rubber and may be spec'd larger by suppliers. The seal is a whopping 11mm wide because it has a flange that pancakes onto the outside of the diff:

(Incorrect, oversized seal sent TWICE by Amazon supplier even after online-chat with sales #@%&! )
I couldn't forfeit more time to source the OEM flanged seal, so settled for an adequate double-lipped substitute, Dichtomatik #2309. No flange, but excellent fit:
