[LH Lead-Foot]

My results did not create too much positive camber. The relationship of the ball joint on the lower control arm from a G20 to the shaft, measured the same as the OEM lower used on the 1967 C10. They did change the lower "U" bolt from 5/16" to 3/8", but everything else is the same. Since I am reusing the upper control arm, with the same shims, resulted in no increase in camber meaning the top of the wheel/tire is further out. I did not find any difference in the later spindles, but I did use power steering specs to align.
Over the years from repair shops to dealerships, I have had to use the alignment machines. I hated it because your only as good as the machine you are using. This take the control away from me. With that being said, the technology has changed from strings, to lights and now laser's. We all know how expensive these alignment equipment are and every few years, they show up with a new type, so it becomes something you're into or not. I quit alignments as I was more than busy in diagnostics and repair.
For manual steering, the camber remains the same but caster is reduced to help the driver turn the wheel while not having the weight of the vehicle to lift as this action occurs due to more positive caster. Increasing positive caster help the steering return to center, so generally, vehicle equipped with power steering have more positive caster with the right side / passengers side with slightly more caster to help with control as that side of the road is rougher. This helps the wheel take the compression and extension produce less force on the linkage.
I did not have any problems with achieving correct caster, while I did increase caster due to adding P/S. Toe in remained the same and the tires wear fine and driving down flat interstates with a light grip on the wheel goes dead-on straight. The relation between the upper ball joint and lower, on the suspension system used on these trucks and many others (SLA) short arm, long arm, are very reliable, but understanding that the imaginary line drawn from upper to lower ball joint, under load, strike the ground & tire tread in dead center results in "Zero" Scrub". Careful consideration of the wheel"s center off-set, either positive or negative has to be considered in changing wheels. I have had many customers vehicle with wheel adaptors, holding wheels with the wrong off-set and it will yank the steering wheel out of your hands, while just pulling onto a service lift rack. Even with power steering, rack & pinion or recirculating ball control box. The latter is not so bad, but driving very far is uncomfortable at the least.
I am not a suspension engineer, but while acknowledging what the engineers are trying to accomplish, was easy to understand during dealer class explanations. Zero scrub is common from the early 90's to date. "Steering Axis Inclination" cannot be changed, it is check third after inspection of components, suspension book height, them rotate left & right to make sure it is the same. This indicates that no parts are bent.
This is one of those subjects that when you ask 100 guys, you get 100 different answer's. I would talk to an alignment tech to ask questions. But the G20 lower control arm measured the same with the only difference being bracing welded on the bottom to reduce flexing under higher loads. Other than that, my side by side observations found no difference. As for the late model spindles, I had the same exact caster, just a heavier casting.