It's a bit more complicated than just the LCA inclinations. You also need to know the inclination of the UCA. From there you can establish the location of the Side View Instant Center (SVIC - most of the drag racers shorten this to simply "IC" because they aren't too concerned with the Front View ICs).
% antisquat can be calculated once you've determined the SVIV location, know the wheelbase, and can at least reasonably estimate the CG height. Strictly speaking, you'd work with the CG height of only the sprung mass (unless wheelstanding).
I know that some of the pricier books (Milliken & Milliken's "Race Car Vehicle Dynamics") and at least one of the softcover books (Puhn's "How To Make Your Car Handle") provide illustrations of the side view geometry for various rear suspension arrangements, and it is possible to construct mathematical models from those. It is also possible to model in the PHB or Watts link and determine things like roll center height and axle roll steer.
All that can be done in Excel, including a geometry plot.
'08 GT coupe, 5M, wheels, tires, pads, fluid, a few suspension mods . . . still almost stock height
'19 WRX, 6M (hers)
'01 Maxima 20AE, 5M (spare, winter driver)