I think the answer is no, but being both A-body's I'm just hoping they work. I have a running 1973 Regal that will serve as a parts car for my 1965 Skylark and wanna get everything I can from it. At the very least, 350/T350, rallye wheels, brake booster/master (will this work?), and whatever else makes sense.
I have seen people do it but I'm not sure how well it works. The 73 to 77 spindles are taller from ball joint to ball joint, so, the upper control arm will be at a weird angle, not sure what that does to the steering/suspension geometry. You may want to measure the Regals upper control arm to see if it will bolt to the frame, that may make it work properly.
Best I remember this was the "hot" swap in the late 70s-early 80s. It required a special upper control arm and equally special ball joints from Global West (maybe others) and you had to swap tie rod ends. It was supposed to improve camber gain. It is less than optimal with all the unique parts. I'd swap in 69-72 A-body spindles and rotors. Not sure if the calipers are the same but are similar and use the same pads. You can likely use the master, booster and combination valve, which will be a lot easier to do while the engine is out of both cars. The parts for 69-72 conversions are readily available.
Ah, found an article that details some of the finer points involved. https://www.chevyhardcore.com/tech-...endly-chevelle-front-disc-brake-swap-options/
There used to be an outfit known as "HO Enterprises" that seemed to be at the forefront of what was called the "tall spindle" swap. Jeff Smith was also likely involved. Believe a heck of a lot shims, were needed, if the stock upper control arm was retained.
I have the tall spindle conversion on my 71. I suppose its outdated, but when I did it 20 years ago it was a pretty good upgrade. 2nd gen F-cars were everywhere in the yards. I bought complete spindles with decent rotors for 20 bucks...
