So this is a project I have wanted to do since I got the car (67 Delta 88).
I ordered the "correct" replacement booster/master combo -Cardone 50-1109. Read all the post on how to do it and started today. First fail, "there will be two holes in the pedal arm for the master cylinder rod, one for manual, one for power". I get under the dash and find out mine only has one hole. Second fail, there are two studs through the firewall (top) and four bolt holes below these. The manual master cylinder is mounted to the two studs and the four bolt holes would be for the booster. The firewall is slotted so that when you drop down to the holes for the booster the rod can still pass through. If you do this, it puts the rod about two and a half inches below the hold in the pedal arm(see fail one). Third fail (I gave up after this), the booster holes on the firewall are 2 3/8" apart. The studs on the booster are 2 3/4" apart. This was supposed to be a simple bolt in but not so much. What gives? Any advice from the experts would be greatly appreciated.

 

According to my research withRock Auto Parts Cardone makes 2 master cylinder/boosters for 1967 Olds Delta. One is # 501109 ,the other is #5481109.I don't know what the difference would be,but this is probably your trouble. Contact where you ordered them and see ! Larry

 

I saw that one too. The difference between the two is that one has the master cylinder already attached. The other is the booster only.