Need some direction for a '68 K20 build

[backwoodsK20]

I bought a 68 Chevy K20, 292/SM420/Rockwell transfer case. Truck runs and drives but is mechanically rough. I got a '79 K20 for parts, which i'll be using the diffs from to transfer to the '68. Here's my plan, any advice on the flaws would be appreciated.

-Remove springs and diffs from parts truck, including mounting shackles, and make them fit on the '68 (frames are the same width so why not, the original '68 springs are cracked anyway).

-Parts truck suspension has a 3" block in the rear, none up front. Is it a good idea to add maybe a 2" block to the front?

-I bought a pair of 36" Swampers on 16x8" chevy aluminums. with the mild block lift, would these fit? Rims have 0 offset. Would I need spacers for the front to allow clearance for steering? are spacers even a good idea?

-Lastly I decided to swap the front clip over to the '70 style.

-Truck needs all new brake system, I picked up a master cylinder and booster from an '86 chevy. brake lines will have to be brand new.

The goal of this project was the to make it an inexpensive build, but at the same time I don't want to take shortcuts that would compromise safety while driving. Truck on top is what I have now. The pic below is what I want it to look like.