What purpose do they serve?? To move castor or pinion angle?Reason for asking is trying to put d60 under a 78 f150 and got my hands on a pair of cage arms with the weld on bracket(guy didnt want to go w/coil spring no more so gotem cheap) Going with 12 inches of lift, do i need to worry about stock castor, 1 guy said 5 to 6 degrees?But on a superlift 9 inch lift you have to install 7 degree bushings.:shaking:

You'll need the 7 degree bushings. They correct for both pinion and caster angle. However, with a lift that large, the caster angle won't be completely stock. It will be off a little bit, but not a lot to worry about. The pinion angle is another story.

If their Cage arm and weld on brackets you wont be using C bushings.

my 4" kit came w/ 7degree bushings...

my 4" kit came w/ 7degree bushings...

Yep, you'll have to compensate with either locating the C's and rewelding them, or drop radius arm mounts