anyone know Rochester 2 Jets?

[shmoov69]

I am putting a 3x2 setup on my 58 and am having troubles with tuining it. First, what is the little thing in the bottom of the bowl by the jets, a power valve of some sort? Is there any tuning it if it is? Next, I have got it running (without leaks!!), but it will not idle at all. It almost seems that it has a big vacum leak or something. Is there anyway to tell where a leak would be coming from or how to verify if that is what the problem is? Is there anything else I should know about doing this?
Thanks!