Need some help after adding an AAL

I recently had a custom AAL added from a local spring place. From center hub to fender now measures 23”. It added roughly 2” in the rear from where it sat. I started getting vibes from 25 to 15 when slowing done. Even though I am stock in front I did the bushing up front. I don’t know if I had shims from factory but the local shop washed their hands helping me solve my issue. They don’t use shims and my drive line looked good to them. So I read for weeks on here and figured how to get measurements but I can’t figure out what size shim to use. I tried the OME drop kit made it worse. I put 400 lbs of weight in my bed. Vibes got better but was still there at times. Any help would be appreciated.
The only thing that confused me on measurements were where to get drive line measurements, it changes from location of the shaft. These #s are from just past the pinion joint. I came up with anything from .5*to 1.5* shims

Front pinion 2.2*(down)
1st shaft 1.9* (down)
2nd shaft 3.2*(down)
Pinion. 3*(up)

 

If you put 400lbs in, that should have dropped it down to where it was before, or close to it, so something must have changed. I doubt they removed the driveshaft to install the AAL, but check the phase of the u-joints.

Most new DCSB's are 22" from hub to fender, so you're only at a 1" lift technically and I sell that and 2" of lift all the time with no mods needed.

Being a 2019, your carrier bearing and ujoints should all still be fine as well.

 

Thanks for the advice. I am going to check the straightness of the drive shaft and recheck my angles this weekend. I do have cap on the back so it might be slightly over 1”.