If you look closely you can see the turquoise Ford Stepside has had the front fenders opened up. It is very suttle but it gives room for bigger tires. I noticed the contrast of the Ford beds I posted up. There are 2 different styles of fleetside (Chevy terminology) beds along with the stepside. A lot of guys like to swap out the divorced t-case and front axle with newer stuff. I have a friend who has a 67 3/4 ton with a FI 460,C6,divorced 205, High pinion kingpin open knuckle disc braked Dana 60 in the front and a GM 14bolt out back. Both axles run Detroit lockers and disc brakes. The HP 60 is a cool swap because it gets the driveshaft up out of the way. For the Ford purists out here he installed the 14 bolt because they are cheap, plentiful and bullet proof. He has 4.56 or 4.88 gears and runs 37 inch tires. It is a great truck for 4 wheeling.
I too am a Chevy guy, GM interchangeability and simple reliable drivetrain are key factors in my preference. The fact that my Mom worked for GM Powertrain for 25 years has nothing to do with it!