Its not so much a sore subject as one you may find not many people here have much experience with. Plus your question is very specific and few of us have exact knowledge of '85 or '87 trucks.
My neighbor once owned a '73 Chevy pickup that was mounted on a '72 Chevy 4x4 pickup frame. He bought it that way, and sold it that way, so he may have little knowledge of how it was done.
I think you'll find some of the mounts close, but others will take a fair amount of work.
