I think you would be fine with this. I think you might have to modify something, as these didn't come with "boosters" so your lines and a possible crossmember fab might be the only other thing you need to do. Copy and past the link below, if you can't click on it. This is for drum/drum. I don't think you will have any problems using this with a GMC frame


http://www.classicparts.com/1947-54-Power-Brake-Booster-Conversion-Drum_Drum/productinfo/71-903/


51' 3100 s10swap, 350, 5 speed, patina
http://67-72chevytrucks.com/vboard/showthread.php?t=382481

49' GMC 3100 future project

55.1' chevy future project

54' 6400 chevy dump truck all original

63' c-10 future project