Power brake vacuum ?

[RShaips]

My brakes do not want to lock up when I slam on the pedal. They stop but it takes like 50 feet, otherwise they work great. I was told that I may not have enough vacuum to the booster or I have a bad brake booster. I have power disc brakes with a 383 Stroker. My vacuum line is hooked up to the back of the carb, I was told to hook it into the top of the manifold to get better vacuum but my Edelbrock intake does not have a spot for it. My master cylinder is new and the brakes have been bled. Any way to check the booster to see if its good or bad ? Thanks