im no expert but i think the caster was around 1 deg, and i think the tubular arms add about 5 degrees. Guys who have modded their LCA shaft by moving it forward 3/4" have gained 6 degrees for a total of 7 degrees.
http://67-72chevytrucks.com/vboard/s...d.php?t=501241
That is a great thread about caster.