now what need some help ASAP booster and bracket dont fit each other

I've got a cadmium plated reproduction bracket here I bought with a box of used brake parts.. Previous owner burned the bolt holes out wider with a torch and it still didn't work. This post doesn't solve your problem but at least you know you're not the first.
I do know there are 2 or 3 different boosters for a-bodies. Their brackets may be different also. good luck