Idle help

[sphooch]

Hi guys, i'm trying to get my roadster to run better. here is what i did. I adjusted the air to 1&1/2 turns out as per the Less Andrews , adjusted the idle speed to around 700rpm,in doing so i found an air leak and tightened the manifold bolts, running not bad but when i shut it down about 3 sec. later i get a back fire?? this seems to be my stumbling block. what am i missing?? any help? thanks THE HOOCH