Not a pro but your new gear set should tell you + or minus on the pinion shim. Use paint or lay out dye to set back lash and check pinion depth. Always a new crush sleeve to set bearing preload
Have fun getting it to crush. Read the books take your time have fun
I would like to do it myself and plenty of info out there to show me how. Gears are just under $200 bucks I just have to figure out what gear ratio I need that work well with my over drive.