S10 to 49 Olds
Glad you decided not to cut the frame. You are going to be happy with this setup. I can't get the Wiki's to open today, so I'll have to go from memory.
As Chieftan stated, the upper control arm is mounted at an angle (from level) for anti dive. I used 8 degrees (about 1/2 inch as I recall). If you are talking about the upper A not being 90 degrees off the frame, yes, it is angled back to create the positive caster.
For spindles, the 58 Pontiac ones work great. I still have a set, as I went with the drop spindles. Drums for the 58 were still available last year from O'Reilleys, or they can be converted to discs.
Note; the lower ball joint mount on the 58 Pontiac A frame is very wide. Other than the stock ones, and the custom setup from CPP, I didn't find any other spindles that would work.
I stacked 1/2 inch of shims in my setup at the static position. Might be a little much, but I had the engine in and measuring to set up both side exactly the same was tough, so I wanted extra adjustment room. Also the extra room allowed me to try several different caster settings. For some reason the car tracks better at 2 - 2 1/4 than it did at 3 +, which surprised me.
Chieftan, did you get yours on the road yet?
I haven't started the Stude. Decided I needed a hauler first, so I'm working on a 54 pick up, with a 500 caddy in it. drop me a line.