I just ordered a Reman'ed 1979 D150 brake booster (2 bolt master) from RockAuto. Its like $72 plus $16 core.
They have the 4 bolt master ones too.

Retired, US ARMY 1973-1994
ASE mechanic, Electrical 1994-1997
Retired GTE/VERIZON/FRONTIER 1997-2015


Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good.

03 Suzuki Burgman 650(Burger King) Scooter
65 Formula S Cuda
78 Little Red Express Truck
98 Buick Regal (wifes car)