Thanks guys, this helps to know folks have made it work with lower than optimal vac.
Appreciate the links to vendors also-good to know some of the parts that have worked well.
This is the reason this board and community is the best.
Thanks again.

Mike Rizzo

1963 F100 "Rudy"

Daniel Island, SC

I have power breaks on my truck,has about 9-10 hg vacuum at idle in gear and  absolut no problems with the break booster.

Riz has a good thought. Electric were used on any GM vehicles that had tune port injection and any thing else that did not have a plenum intake structure. I used one on a small displacement engine as a crankcase evacuation system a few years back. It was Suzuki's way of winning at the NHRA drags for a few years.
In wrecking yards they are normally mounted behind the headlights and in front of the tire. I believe their AC # is 215-425.... Good Luck

56 Vic, B'Ville 200 MPH Club Member, So Cal.

You might try ABS Power Brake http://www.abspowerbrake.com/maincatalog_frameset028.html

They show a dual 8" unit, which should be more than enough at 15". I'd guess even an 8" single would work. If the pedal ratio is good, and you can fit a decent size vacuum unit, it's like Charlie says.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

   I have a 1977 Mustang Cobra II that has a 600 lift 254 duration @ 0.050"  roller  cam and  power brakes  What I use is a SSBC Electric  vacuum pump kit!
This solved my  poor brakes problem on my car, I would recommend it to any body that wants power brakes with a Wild cam!

A friend of mine has power brakes on a vehicle that has 9" at idle.  Lower than what is said to be ideal, but it seems to work.



Lawrenceville, GA

If you have a vacuum guage in your car or can rig one up drive down the street as you normally would and as you come to a stop applying the brakes look at the guage... It's probably higher than idle vacuum. Brakes are normally applied in a slowing down of your vehicle when the vacuum is at its higher number and that's when the booster comes into play helping you stop.
You could always add an assist booster to the left inner fender like the early Birds and full size Fords did as an add on..... Good Luck......

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Thinking about adding a brake booster to my 63 f100, it has stock cam original 292 and G heads 3x2 carbs. So vac would be from a boss I put in the manifold. Mustang II ifs disk brake front and drum rear. Runs about 15" vacuum at idle-little light, but not worthy of a rebuild. Also has TH 350 AT that pulls some vacuum. (I know-I knowbut you can build the 350 to avoid needing a kick down run to the carb unlike the C4 which is a blessing on a 3x2) I call it the original "hybrid"

Question is would that be enough vacuum to run a brake booster or should I just spare the agony and look at a firewall electric vacuum pump. There also could be some space issues for a booster and the valve covers.

Would hate to buy and rig a booster and find out it takes too much vacuum, and undo it.

Thanks in advance..

Mike Rizzo

1963 F100 "Rudy"

Daniel Island, SC