There are two settings on this particular style of hanger.
I used the lower of the two. It dropped so low I ended up
having to reinstall factory shackles,Now I have a harmonic vibration.
Shims are not installed at this time.
Would it be best to shim the rear end or take the leaf spring to next level and install 1/2" shackles to the lowest setting?
Any advice or suggestions will be greatly appriciated.

 

Put the hanger at the highest position and determine the adjustment of the shackles depending on what you are looking for.

I've spent allot of time on this and this is what has worked best for me:

hanger at highest
shackles at lowest
add traction spring from JC whitney $59 which adds spring rate and prevents bottoming and enables you to add up to 3/4" if desired.
6 degree shim works perfectly with zero vibration
foam filled bump stop to protect from bottoming

Many have commented that I have the best all around suspension they have seen including an SVT engineer at an On Track event. (I've done other stuff of course)
Good luck

Red

 

Belltechs put me 17". Highest on hanger and lowest on shackle
put the rear end at 15-3/4"
Factory shackles put me just a hair below 17".
I'm looking for a slight rake rather than a slight drag.

I planned on going to the lower setting on the hanger in the morning and the highest setting on the shackle.
Hopefully that will give me what I'm looking for.
With any luck I'll lose the vibration so shims won't need to be added.
I appriciate your response. I'll keep the traction springs in mind.

There's a mis-print on original post. I used the higher setting of the two on hangers.

Ron