want to adjust my pinion angle,not worried about traction,drag racing,just getting the angle right.so do i go upper or lower?

 

lowers are easer to install and adjust! either one will set your pinion angle!

 

+1
Just what I replied to you over at the other site

 

fix.t

 

Actually if you want to maintain axle position ... both

 

Amen! Changing the pinion angle effectively changes the "caster" angle of the rear axle, which in turn rotates around the center of the LCA axle-side mount bolt (if adjusting the UCA) or around the UCA axle-side mount bolt (if adjusting the LCAs). Having both adjustable allows you to not only adjust the pinion angle, but completely recenter the axle laterally and longitudinally. Throw in an adjustable panhard rod and coilovers, and you've got as much adjustment as the average race car...

 

I would go adjustable spherical UCA with fixed LCA's and if you are lowered...LCA relocation brackets with adj. Panhard.

 

If you are not willing to do both, then either one is right, but not best. Simplest is upper (only one adjustment), but its not the easiest to adjust. Lower is easiest to adjust from an accessibility standpoint, but you have to adjust both sides with precision , else you will induce some rear axle steering.

If you go with spherical brg as suggested, expect to inherit more rear axle harshness and noise.

Have fun.