I just noticed that our '87 is showing what looks like excessive negative camber on the left rear.  The right looks normal while the left appears to be tilted in further at the top.  I put a straightedge level across the left wheel arch at the top of the wheel and measured 3/4" from lip of the rim to the straightedge, while measuring the same way on the right gives 1/4", so about a half-inch difference from one side to the other, about what it looks like when viewing the van from behind.
I usually keep a pretty close eye on chassis stuff; checking tire pressures regularly and checking the tread for wear and FOD (good old Air Force term for Foreign Objects/Debris) so I feel like I'd have noticed the camber thing before now.  Tires are fairly recent with low miles being driven so there's no tire wear to indicate a camber problem; it's just something I spotted. I'll get under there to see about adjusting but is there anything specific I should be looking our for? What would cause the camber to just go out of whack?
Thanks!
Stephen