If you pull an OE booster to put in an aftermarket POS your a fool..... I just went through is with a guy with more dollars than sense... He started having a hotrod shop rip out the old OE Bendix booster & install a new MP booster.... The car stopped terrible, they replaced the MP Booster three times... Then they sold him a Hydraboost system... It stopped ok but the pedal always felt weird, kinda like a HD truck... Finally I got talked into looking at it... Now it has a rebuilt OE Bendix booster, a new master cylinder & it stops like a new car.... So after spending $2700.00 he has what he started with...
Get your stock booster overhauled, Sell Alan your stock MC core if it's the pt # he's searching for & put a new stock MC on the car... If your looking a Wilwood brakes or something like that you might need a different bore size on the MC but keep your stock booster....