Results on Belltech's 1-3" Rear Shackles...
 

I think my starting measurements for the back left were off, maybe the groung was uneven. Ill still post what I got. My measurements were as follows....

Before
Back Left 34 1/4"
Back Right 33 1/4"
Back Bumper 17 3/4"

After
Back Left 32 1/2"
Back Right 32 1/4"
Back Bumber 16"

Difference of
Back Left 1 3/4"
Back Right 1"
Back Bumper 1 3/4"

I set the bolts in the lowest setting possible, so these results are going to be as low as you can go with these shackles.

What year is your L by chance?

2001