Switch to manual brakes makes car run better?

Just an update for anyone stumbling on this post later. The car running better is definitely not in my head. I don't generally run it too hard but decided to do a little testing Monday afternoon. It actually will break loose the right rear punching it from a 10-15 mph roll and it will burn the right rear until you let off from a dead stop. I'm not at all into burning tires cause I'm cheap but I figured seeing that it would do it now pretty well proves that it's running much better. That apparently bad rebuilt booster had been on the car since 2012 and the engine has always pulled 17-18 inches of vacuum at 650 so I never dreamed I had a problem. I just figured the 2.76 gears and lack of headers were holding it back. Makes me wonder what other tuning issues I have killing 20 or 30 ft/pounds of torque.