[thecatseye66]

Welcome to the board!!!:
Check out this thread in the FAQ's (lots of great information there):

http://67-72chevytrucks.com/vboard/s...ad.php?t=13692

OR, you can swap the entire crossmember, but you have to elongate (egg-hole) some of the holes in the frame to make the newer crossmember fit. You also have to use the newer MC and proportioning valve to accomodate the front discs. Some guys have gotten away without changing the MC/prop valve but the pressure is different and you will have less stopping power (which is why you'd want to do the swap anyway).

Good luck--