“......What kind of Dana 60, I got a spare 68-70, will it fit in my 37?......”

I’m going to be using a 69 B Body Dana. It’s about 2” wider than the 58” wide 10 bolt Nova rear that is currently under the truck. That’s only an inch on each side which may make it a bit close with the wheels that are currently on it (8” wide with 3” backspacing). I’ve got some different wheels with 4” back spacing I’ve been kind of thinking about using anyway.