I installed a holley 670 street avenger on my 85 blazer 305ci. The only problem is that now i have to wait a good 5 to 10 min before i can even drive the thing because it keeps stalling out or back firing. My choke is fine and so is my idle mixture and vacuum lines. Can it be the carb is too big or the air pump(it is still connected) /forums/images/graemlins/angryfire.gif /forums/images/graemlins/k5.gif p.s. The engine is stock as well as the exhaust.