Disc brake conversion

[62much]

Well I finally bought another money Pit, 1969 C10 SWB, 350/350. The truck's in pretty good shape, and the PO had put on a disc brake conversion, or at least half of one anyway. The truck was a manual power brake truck, and the problem I see is that he kept the stock Master/booster & prop valve and just made it work... no wonder it doesn't stop worth a damn Now I've done a few disc brake conversion before, but they were manual w/o a power booster, and I just added the new booster with everything else. My question is... do I need to replace the booster along with the Prop Valve & Master, or will the stock booster work. I was hoping not to have to do this again, but you really have to check other peoples work when you buy these old trucks