Saw my name, yes I do make fully adjustable uppers, with tall ball joints included, not "in the works" they're on cars right now.
Forged aluminum cross shaft, chromoly PTFE lined heims, 6061 adjustment tubes, QA1 tall ball joint. No messing with shims, gives max header clearance (no bushings in them to melt either)
$420 shipped, lead time is 2 days. Theyre pretty much the same as the SPC arms, just no bushings and mine are cheaper, including the ball joints which they omit.
Obviously I am biased but I dont think you can get anything near as good for the money, best on the market.
For not much extra I can even include a way to adjust ball joint length
As I told a guy the other day, all you are gaining in an aftermarket lower is the look, and moving the ball joint forward to counter moving it back up top, not "necessary" but I tell people its up to them. I made lowers for a while but I was doing them from scratch every time and it was hard to maintain a consistency & work flow. A friend is buying a bendtech dragon, and another bought a crossfire CNC table so I may come back out with my own, Ive been recommending UMIs lowers in the meantime They move the LBJ 3/4" forward to counter adding caster up top, and I like the guys over there so.