I have a question about brake booster . My car is a 78 which came with standard trans . Now has 02 LS1 with auto trans . Noticed the brakes kinda weak to hold the car at idle , really have to press hard on pedal to keep it from creeping and it idles only at 600 rpm . Brake sys. is stock with 8 in booster . Thinking about installing a 10 in booster . Question is has anyone done this and how much improvement will it give ? Thanks .