Guesstimating a level ride height

[IvelDesigns]

So I'm here, and my truck is two hours away. I'm thinking to myself, how i can ensure my ride height is pretty much level front to back when i install my bags.

my plan is to do the rears first (all of the parts are sitting with my truck right now) and the do the fronts in a few weeks. I will have the whole back half tore down because i am also dropping in some new trailing arms. I figure then is the best time to add drop blocks. problem is, i don't know how much of a block i'll need to get the ride level.

up front i am using a 7", 200PSI slam specialty bag with cups that i plan to cut down to 1-1.5". i am using the same bag in the stock coil location in the rear, and installing a CPP notch.

What size block should i get, if any, to get a close to even ride height?