compression help

My engine idles at 6" of vacuum, and my power brakes work excellent on my 1970 E-body. Rebuilt factory booster, 11 3/4" Police/Taxi rotors and Dr Diff's eco no rear disc brake kit.

Not really sure why they work so well on such low vacuum, but they'll drag the car down from deep in the triple digits with ease. They work great around town too.

I have the exact same brakes on my 1968 A-body with a manual < 1" master cylinder bore. That system gives much better feedback during critical light braking situations and doesn't require excessive peddle pressure to lock them up, but it is more effort than the power brake system to go into lock up.

Both cars weigh roughly the same. If my 1970 didn't come factory with power brakes, I wouldn't hesitate to run this same system with the manual set-up.