I know it may be too late since you have the new stuff, but you may want to upgrade to a dual circuit master cylinder for safety reasons. you then have 2 hydraulic circuits so if one circuit has, say, a leak etc, the other circuit is available to stop the truck. it would give you a front circuit and a rear circuit from the same master cylinder so a safer option than relying on a system that fails everything at the same time.
here is a thread that talks about it and has some options. you could also try the vendors to see if there is a bolt on replacement. if it concerns you.
http://67-72chevytrucks.com/vboard/s...d.php?t=617103