Looking to install PB and front disc's on my 69 4 wheel drum car. I have tall valve covers on a BB and the original boosters won't clear. I've heard that the S-10 booster will work but the S-10 I just looked at seems to be about the same size as an A-body booster.
I looked at a corsica and it had a very small booster,(about the size you see coming with some of these aftermarket kits). I talked to a guy at a car show this weekend with a BB and tall V/covers that bought the small aftermarket booster and was pissed, cause he paid over $400 for it :eek: and then heard of guys using the smaller booster from other GM applications.
I'm sure someone has done this and I would be grateful if you pass along ANY info I my be able to use to my the swap succesful and easier. graemlins/thumbsup.gif
Also the corsica booster had a master cylinder with 4 lines coming from it and I couldn't see a proportion valve anywhere from looking at the top of the engine.

Thanks for any and ALL input

PS

Also in need of disc spindles if someone can help a brother out.

The problem with the smaller boosters is they have less diaphragm surface area than their larger cousins and thus need MORE vacuum compared to a larger booster to function properly, typically 16" minimum.

If your motor makes good vacuum, then a small booster wouldn't be a problem. If you don't have adequate vacuum, there are a couple options-- an electric vacuum pump to make up for the lack of adequate vacuum, or my personal preference, a hydroboost (http://www.hydroboost.com) (if your car has p/s, it's an easy add-on.)

The dual diaphragm boosters off F-bodies will work with a few mods to the firewall adapter and also a mod or two on the rod for the brake pedal; do a search, a few guys here have done the swap and documented what needed to be done. Master Power Brakes offers boosters as small as 8" I believe, but again, they will need a lot of vacuum to provide a reasonable amount of assist.

Troy

What would be the min vacume and where would you take the reading, from the manifold where the booster would draw from?

Thanks

I did read about those PS boosters your speaking of and they sound really nice, BUT I've nearly max'ed out the budget and everything is complete except this swap and the 12 bolt.

i just installed 8" corvette booster on my 69 suggested by mpbrakes.com..

Take a reading from the large fitting on the back of the carb or from a large fitting on your manifold-- either are good places to hook up the booster. (Don't hook your PCV up to a port on the manifold though.)

If your car is an auto, take a vacuum reading in gear, and if you have A/C, turn the A/C on too, that way you will get the lowest possible vacuum reading.

If it dips below 14" in the conditions above a small booster probably will be very spotty in slow speed stop-and-go stuff; you will probably want to consider an auxillary electric pump and a tank. However, give it a try without the tank/pump first and see if it works. If it does, great, you just saved a few hundred bucks. If not, buy the pump and tank. You will want an accumulator tank if you have to go with an electric pump so the pump won't cycle on and off as much.

Troy

I'm running tall stamped steel valve covers on my car with original brake booster,I've got 1/2 inch clearance and can get the valve cover off no problem :confused:

Johnny69 what year vette booster did you use?

Robert are you using roller rockers?

Troy I guess I want the reading taken at idle about 600 RPM?

aclineman,i purchased it from master power..mpbrakes.com not sure what year but i told him my concern with room with the bb so he sent me that....