Where to buy disc conversion

SSBC conversion kit comes drilled for both 5x4 and 5x4 1/2. Easy conversion bolts on exsisting spindles just drill out two holes to a larger diameter [NOTE:must have 10 inch drums to use spindles for this conversion, if 9 inch brakes must use different spindles] in that case go with junk yard parts and a new master cyl. as yy1 says. I purchased my kit due to [A:im impatent B:too lazy to hunt down the parts] plus i had 10 inch drums.