Ahh. I see. So in my case correcting the caster did just that, but increased the pinion angle. Which may be the cause of the vibration. Which a dc shaft would fix. Or if I understand correctly if I go back to my old radius arms and less caster the vib would be gone again? (Pinion angle less) I could do that , I guess the sacrifice would be the better handling from corrected caster...
Correct, It’a highway wandering vs potential driveline vibration when getting over 2” in height. Two inches and caster correction and 4” in height, a DC shaft and correct caster are the usually the sweet spots.
There are some really old threads here of guys correcting it my putting their front driveshaft in phase and rebalancing it was enough.
Of course dunderheads like me started running 3” lifts, 3.5” lifts, tapered springs, etc and started muddying up the water.