Mounting Blazer Tub to the Frame

[BLT-NT-BOT]

I just got my tub and frame painted and I am ready to mount them back together. I bought a mounting kit from Wes (which looks fantastic) My question is where do I start? When I pulled the body it had several shims between the tub and mounts, but of course I didn't track what went where. Any suggests on using the shims, not using shims and how do I know if I even need the shims? any advise would be greatly appreciated.

thanks Jothan