Thinking of converting to Manual Brakes

On my C body, plus B & E bodies (I think), the booster mounts directly to the firewall. That is typical of most cars. In all Mopar A-bodies I have seen, the booster mounts on brackets that stand it away from the firewall, and more importantly higher than the pedal rod so that it clears the driver's valve cover in a small block. The later might not be a problem in a slant, but I think they used the same brackets. At least I recall I got the booster setup in my Dart off a 74 Dart slant. In between the pedal rod and booster rod is a lever. The lever greatly reduces the force applied to the booster, hence they used a smaller bore MC on power brake cars. GM A-bodies don't use a lever. Instead they angle the booster upward and use a different hole on the brake pedal for power brakes.