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

so im converting my car from man breaks to power disc
i bought fire wall mounting bracket from the guy at sweet water on here
bought booster and master from auto zone
guy who i got all the breaks from said get a booster from a 76 it works just fine no problems

well the fire wall mounting bracket holes do not line up with booster studs there about 1/4 off and there squeezing the rod and rubber boot A LOT if i force them to the studs the one on the rear of master that the rod goes threw

some thing is clearly off and it seems like a very tight fit to valve cover and wiper fluid tank i know its tight with the big booster if i can even run it
but seems like its to low by like a inch maybe the bracket? maybe the large booster


im not sure if the fire wall mounting is incorrect or the
booster is different in 76 and will not work with early a body fire wall mounting bracket some one has got to know whats going on
the car is a 68 340


thanks