Phew,
This seems to be a loaded question as there are so many variables.
a) A-arm itself
b) Chassis / suspension variation
c) Tire and wheel combo
d) Spring articulation and rate
No?
Not sure that these cars were tweaked to such exacting standards as it seems to me the old way was a more Mike Tyson approach, go hard and do not break.
Did SAI truly set up specific adjustments on the earlier buggy cars and/or even the 427 chassis? My guess the 427 was far more adjustable and the 289 were more hold on and be fast and win?
Just trying to point out at some point the calculations might be better served with getting your car done using basic common sense. Remember the spring articulates as it compresses thus your camber changes depending upon the spring arch and its rate. I am somewhere around 1.5 (memory) but again, to make it perfect might be a huge challenge. However I am not that smart so I may be way off, Cobras were loaded with variation.