Lowering a 72 C10 with rear leafs

[Arizona oldguy]

I am new to the site and starting on a new project, I have a 72 short bed frame with rear leaf springs and factory front discs, I am putting a 67 cab and front end on it. I want to lower and level the truck. I am choosing 2" drop spindles for the front and shakles for the rear, question 2" in the front how much in the rear to make it sit mostly level? any help is much appreciated.