I have a question for you brake guru's, everytime after I start my Blazer and put my foot on the brake pedal before I put it in gear, the engine idle raises a little, is this normal or what? Now I have owned GM vehicles all my life and this has never happened on any of them. The only thing that is different about my engine is, it's a 0.60 overbore 350 with a summit camshaft that has an advertised duration 272/282, Lift .442/.465, with a lobe seperation of 112 degrees. The brake booster is used from a junkyard, it had some type of canister about the size of a fuel filter between the carb and booster that I took off because when I blew thru it there was no restriction from either end, so I thought whatever purpose it had served it wasn't serving it anymore so I took it off. What is it for? Ever since I've owned this Blazer it's never had very good brakes no matter what I do, new master cylinder, calipers, lines, I have even rebuilt the rear brakes. WTF?