"F" 100/250 4x2 (1965-72), "F" & "P" 350 (1968-72)
Caster adjustment is accomplished by twisting axle outside of radius arm attaching point.
CAUTION:
Do not heat axle to twist.
To increase caster, twist axle in rearward direction from top. Twisting axle in forward direction from top, will decrease caster.