[rickoner]

I thought about doing just that actually. But when I was really checking out the builds that used them it looks like it positions the box using the steering and sector shafts since the box ends up inline with the steering shaft. Maybe there's more to it?
I did get around to taking measurements off of the '86 frame tonight tho. It seems like just measuring off of like points is going to be the easiest way to ensure it ends up where it needs to go. I won't know for sure until I get to check out my '65 frame. Unfortunately, it's at a buddy's place getting the patch panels finished up (hopefully). I'm basing all measurements off of the three mounting holes on the bottom of the frame rail. I figure that will keep the box/linkage/crossmember/spindles as they were originally designed for the '86 truck. The plan is to lay it all out and clamp it together at 2" raise and see how bad it really is.