I am trying to change my master cylinder from drum/drum with no booster,to disc/drum w/power booster the old M/C set level and the new one is tilted up so it will not hold as much fluid.Why do they do this?

That's just the way they did it and it's been that way a long time on more than just 69 camaros. I think it's because of the hole being lower on the peddle for power brakes. I think the rod would jam if it came straight thru the f/wall. As long as you have it filled and you don't have any leaks there is nothing to worry about.

Power brakes ease the pedal effort of course, this provides the opportunity to reduce pedal travel by half. The way they do that is to connect the booster pushrod to a hole that is lower on the brake pedal. The pedal ratio falls from 6.25 to 1 manual, to 3.8 to 1 power.

The power brake pedal height can be reduced and made closer to gas pedal height, making it easier for the driver to move his foot back and forth from gas to brake.

If the booster were mounted level, there would have to be two holes in the firewall, one for manual, one for power. There is often not clearance for the booster in the low position either. Some GM cars and trucks do have the booster mounted level.
David
David

I have heard from a couple of sources that the M/C was tilted on those cars (Camaro and Chevelle) because of a clearence problem with the inner fender well. They were supposedly tilted to keep the brake lines off the fender well. Don't know..just what I heard.

Tilted clears the big block valve covers. Just barely. If it was straight and power they would not clear.

Troy