4x4 conversion

[tx1969burb]

Good evening, I am new to the forum and love all the info I’ve found here! I’m just starting a frame off restoration on my grandfather’s 1969 Suburban c10. I currently have the body off the frame and before I start the chassis restoration I want to explore the idea of a 4x4 conversion. I’ve spent every night this week sifting through the plethora of knowledge on the forum and from what I understand the easiest way to add 4 wheel drive is to find a 67-72 factory 4x4 suburban or k10/20 pickup and swap the frame (some fab required on the p/u frame). The problem is I’m having trouble finding a donor vehicle.

Will the frame of a 74 K20 mount under the burb with limited fabrication? If not are there any other models that will?

I really appreciate any advice!