Desc brake conversion from a van?

[mtndewmaniac66]

I have a question regarding a disc brake swap from a Chevy 1/2 ton van. I have read, followed links, and even copied posts, but I do not see anywhere on if a cross member, or other suspension/brake components are interchangeable. Of course I will be also using the rear axle in order to keep the lug pattern the same all around. (I can cut/reweld perches and mounts) Can anyone shed some light onto this? Trucks are becoming less popular, (oil field use) and full size vans are becoming more popular. I have a source for a 1978 Chevy Endura 1/2 ton for only $100.00. (no engine or tranny)