My truck does have the front disc brakes. Also, the info that I have is that both master cylinders I was looking at have the same 1 1/8" bore size. I had looked at '69 and '70 master cylinders and the size difference was considerable, to the point that I wasn't comfortable trying them out. I think I will try out the one I have and see what happens. I am definitely going to take down the casting number off the old one and hold onto it though. Thanks a lot for the info, guys. It's appreciated!
