Now that I ready to do my front disc conversion on my 71, I have run into another problem. The tall valve covers on the single booster hit the cover and with a little torque it could break it.

I thought of going to the dual one but I have heard that they require as much if not more vacuum to operate and I have a 280 cam that doesn’t give me a lot of vacuum to work with - <12 usually. I really don’t want to have a vacuum pump running all the time. Do the vacuum cans work well enough for a weekend / street car ?

Are manual operated discs as functional and safe as the power ones ?

Thanks !

Tom

What kind of calipers do you have? I ran my stock discs as manuals using a 15/16" bore master cylinder and it stopped great. Pedal effort was actually quite low and throw was good. The MC application is for a 77 A-body, 6 cylinder, manual discs.

You will need to make new MC to distribution block lines as the 77 MC's front port is for the rear brakes and the rear port is for the front brakes.

If you still want power but still keep lots of clearance, and also have power steering, you can do as I just did on my car and install a Hydroboost (I got mine from Hydratech Braking systems -- www.hydroboost.com (http://www.hydroboost.com) ). They're seriously awesome units. The brake pedal feels the same no matter what the engine load/vacuum, and it produces a TON of assist while still maintaining an excellent pedal feel, far better than a vacuum booster in my opinion.

Troy

You can always run a Supplimental Vacuum Pump from a mid 80's GM X-body ($20 at Junk Yard) They don't run all the time just when the vacuum is low like after the brakes are hit a few times. Make sure you get the entire rubber isolated mounting bracket. Check out where to find one here:

http://www.gmcmotorhome.com/tech/vacuum_pump/index.html