Originally Posted by cobalt327
0.020"-0.040" is the baseline setting (about square, or open as far as the slot is wide). It is not at all unusual or incorrect to have the primary transfer slot at 0.040"- in fact that's more common than less if there's any kind of performance cam involved. The baseline for the secondaries is almost closed, then open as needed to get "bypass" air.
I should point out that the secondary bypass air is used only if the primary side cannot be adjusted to give a good idle by using the idle mixture screws and the curb idle screw.
If you have to open the transfer slot too much w/the curb idle screw- THAT is when you start to use the 2'ndary side to add bypass air to get the idle right. This is preferred by me to drilling holes in the primary butterflies. But this isn't required unless you have a fairly radical cam- so what are the cam specs?