Cab cart info needed

[GMC Rodder]

Hey guys,

I'm finally getting to the part of the disassembly of my 49 GMC where I need to build a cab cart/dolly.

I've found a couple online but I need some clarification on dimensions.

What size do I need to build this thing to support the cab properly?

I'm going to post a couple of pictures of what I'm after. The first one is what I want to build. Out of 2x4 as well as some harbour freight dollies.


The second is the AD Engineering one.

Ideas?

Thanks a lot.