To check Caster I used a 1 inch square extrusion running from the lower ball joint nut to the upper A-Arm center in line with the upper ball joint and then aligned the lazer and read the degrees directly. Setting is 4.5 which is a little high but reasonable. I used the same square tube to read Camber directly.  The adjustments are made for Camber and Caster utilizing the lower Cam bolts.  The forward adds more camber while the aft adds more caster.  Both will affect eachother so you will need to play with both while continuing to check your angles.  Measure Toe last. Camber on the front is .2 deg. Toe is 1/16th utilizing plumb bob dropped from the tire face (Front and rear and marking the floor.  Then measure difference between front marks and back marks of left and right wheel.

Verify your thrust line (center of car) by shooting the lazer from front to back and marking the bottom of the floor pan, diffuser and the forward spoiler lip.  All points can be seen from rear. Then measure from the center lazer mark by leaving the lazer on and pushing a long ruler or tape measure until the lazer light is barely visible at the tip at the center of the car.  Mark the floor approximately 41" from the center to the left and right of the car at each wheel.  Ensure your 41" marks are ahead of and behind each wheel to get a reference to ensure Toe adjustments are centered and do not favor one side.  Toe should be set by equal left and right adjustments from center or the Thrust line.

Whenever adjusting Caster and Camber, re-check your Toe in.

Reference the GTM manual and Corvette Service manual for settings.  Also research to understand what the adjustments will do for driveability.  Variations can be made by researching mild to extreme settings.  The GTM manual is simply a same and relatively mild street setup.