I got a good unit with all the bolts and brake pedal. I need $120 for it plus actual shipping. Where you located.
No vacuum block. It does have the check valve and the hose to the brake booster.
86 -87 Gn or T-Type never had vacuum brakes. ALL were powermasters. Now if you still need a nice complete (minus vacuum block) vacuum brake conversion the one I had for sale just could be again as the guy hasn't got back to me or sent money.? I'm giving him until tomorrow night and then it's for sale again.
Honestly every G body car from 78-87 had the same vacuum brake system the four bolts going into the firewall are all the same.
Besides buying a used unit, I believe a Remanufactured Cardone unit runs about $150.00 does not come with a check valve or Brake pedal. My price is what used units are going for anything cheaper you need to go to a U Pull it junkyard.
Honestly they are NOT the same as the earlier years 78 to 80-or 81 are single chamber master cylinders, not dual like the later years.
Don't they all bolt up the same. Sorry never owned 78-80 G bodys. Only 81-82 cutlass and then my buicks
They may "bolt up" but they don't perform the same, and the master cylinder winds up closer to the fire wall making one having to bend the lines to an odd angle.
I sold a set up last week and it's already installed and the buyer called me up and thanked me already for the tips and advice on how to do it .

Still got 2 more setups