Need help! I bought a brake conversion kit and am having trouble getting the booster/bracket to fit. The 8" booster is hitting the valve cover. Needs another inch or so to fit. I'm told the 7" will not have the power to stop the car. The 11" slim line was recommended also, but I don't want that BIG bugger under my hood! :))) What size booster/bracket kit will fit the 409? HELP!!!!