'63-up front cradle assembly...I think all the way up into the '80s.
Do a search on here, 67-72chevytruck.com, and Jalopyjournal.com
It's a pretty common swap, and from what I've read, it's as simply as six bolts (and drilling holes for a couple of them)
I'm ALWAYS leary of any Mustang II swap...the control arms and spindles were designed for a very, very light car that made no power, and guys are putting them under '69 big block Camaros now. Plus, the geometry of the control arms was designed for a vehicle with a pretty narrow width.
I'd look at the later Chevy truck set-up, with a quick ratio power steering box.
-Brad
