[13jraven]

Got to start with wheel base and overall length.

Denali Suburban vs Crew Cab Dooley

Wheelbase - 116" vs 164.5"
Overall length - 203.9" vs 211.8"

Then see how you are going to put a body that requires a 164.5 wheel base on a chassis with a 116" wheel base.

Are you planning on making the crew cab a short bed dooley?

Lot easier to section a frame then to add frame rail.

And can you make body mounts? The suburban frame is dramatically wider than 80s frames.

Give the google a shot or ask the guys at Pirate4x4.com - they are very accommodating.