Hi Webb,
I don't want to confuse you mate. It would be a good idea for u to post some pics just to make sure.
Some pics like I have below. There are so many differences in parts in the 70 series.
Clutch master. An inch to the right from the bottom clutch master
mouting bolt is the vacuum connection.
Other random pics.
There are a couple of different boosters for the shorty and mwb
70's series. Post some pics and it will make things easier.
Also my booster has a sticker on it with a part number. Have a
look if yours has one.
Cheers.