If you don’t have a budget it makes it easy.
You can get higher end adjustable remote reservoir shocks from Icon or King and use heavy duty leaf springs in the rear to make sure you get the 3” you want. I would use
@DobinsonsUSA or wait for
@ARCHIVE for leaf springs but there are other options we can discuss as well.
For the front get “heavy duty” springs which will likely have a 730lb rating, which also kind of help with the 3” you want. Then, if you still have a rake and you want the truck higher, you can adjust the shock itself to get it level.
This comparison of mine might give you some insight on what 3” could look like?