Choosing the right shims for lift?

So I am installing my new lift this week on the truck. I have 2.5" billies up front and 2.75" dakars out back with new shocks. I have read most people need shims. How do I know which shims to pick and should I put these on when I do the initial install? Thanks!

 

I could use this info too. I have a vibration pulling away till about 20kmh since I put 2" AAL on. All u-joints are good, carrier bearing dropped 1/4" already.

 

there is a pretty easy way to calculate what you need using a digital angle finder. Measure the angle of the flange at the transmission and at the pumpkin then measure the angle of your shafts. Your goal is to have no more than a two degree difference all the way through the driveline from piece to piece. With such a little lift you should be able to resolve it just at your carrier bearing by adding more shim there. You can buy a handful of washers and keep adding or subtracting and remeasuring your angles as you go. The reason the exact same fix does not work for everyone or why someone can't just give you the magic fix is primarily that the arch of the leaf springs is never identical from truck to truck. IE: the angle of the springs where they attach to your axle...which can also change a hair as your springs settle and soften.

harbor freight digital angle finder is cheap and adequate. There is a great thread on here with exact instructions for measuring if my explanation is too vague.

 

I've tried the adding and subtracting shims from the carrier and what I have now is the best, I was going in 1/8" increments, have to try to measure the angles to see if I'm out.

 

I had a slight vibration between 30-40 MPH after my lift. The 1/2" bearing drop took that away pretty nice for me. I still feel like there is a very very light vib in the pedals but not enough to shim the truck.

 

^ this i have some light vibes in the pedals around 60km/h but not sure how/if i wanna approach trying to get rid of them

 

My issue is when I'm pulling away from a stop. Driving at speed I have no issues. I've had the shaft out and all the u-joints are ok and the steady bearing is ok.