Welcome to the Stovebolt!
Though I've not lived there in 25 years I graduated from a Southern Idaho high school. What part of the state are you in?
I believe disk brakes were an option in '71 AND six-lug? I'm not sure of that, but I think someone told me it was the case.
Starting in '72 all Chevy/GMC 1/2-ton pickups have disk brakes, and the suspenion is the same basic design as your '68. But they are all 5-lug. I am sure of that, I have a '72 parked outside.
