Vacuum Port on Carb or Intake Manifold for Brake Booster

[72_Supreme_Conv]

I have recently installed a set of Stainless Steel Brakes Corp (SSBC)power front disc brake set for my 72 Cutlass Supreme 350 Convertible. It had manual drum brakes that I used to call power when I would use two feet on the brake pedal. I have a Rochester 4 bbl carb (7042250). The new brake booster requires a vacuum port. SSBC said that I need to attach to the base of the carb or on the intake manifold. Can anyone recommend the most ideal location? What kind of fitting should I use?

Thanks in advance for your help.

RICK

[rocketraider]

Either location will work, and Olds used either a port at the rear of the carb throttle plate, or a fitting threaded into the intake manifold on the firewall side of the carb to supply vacuum to the brake booster. Check and see if your carb has a large threaded plug at the back; if it does you're home free. Get an appropriate brass fitting, install it and connect the booster to that. 3/8" ought to be big enough.

If it doesn't have the plug in the carb or fitting in the manifold, things get a little tricky. You'll have to either change the carb or drill and tap the boss in the manifold (they all had them, they were just left closed on non-PB cars). That's an uncomfortable thought, getting drilling debris in the intake.

I think you'll find the threaded plug in the carb (or maybe a pipe plug in the intake), since Olds offered dealer-installed PB conversion kits for drum brake cars and they wouldn't have made an accessory installation any more difficult than necessary.

[72_Supreme_Conv]

Thanks for your response. I actually guessed that the threaded plug on the intake manifold to the rear of the crb would be just the trick. I brought the plug to the hardware store and found a good 90 degree barbed elbow to use. I started the car and checked for vacuum and got a reading of 18. Didn't check whether it was inches of Hg or other. I was just happy I was getting vacuum. I think that should be a pretty good number. Tonight I bleed the brakes and finally get this beast back on the road after a 4 month vacation in the garage. Gonna be nice to have power brakes. I have had many visions of a smashed up front end in our infamous Atlanta traffic. Thanks again for your response, as I find that there are many fewer responders on this forum than on my often used Ford Tractor Forum (48', 56' and 61').

RICK