If you are just looking to run the 5x4.75 bolt pattern you could run a 91 Camaro 1LE rotor and use the trucks bearings and brake. it is supposed to give you the smaller bolt pattern with just changing your rotors.
this is of course for the 81-87 front ends. but would be an easier option to swap in a newer crossmember and just run different rotors.
http://67-72chevytrucks.com/vboard/s...d.php?t=319487