Holley carb issue?

I recently had an issue with my car bogging down and stalling. First, check your plugs, they can give you alot of information. Your car is delivering all the necessary things ie fuel, air, spark... but you are not able to sustain the mixture of these elements in a way that will sustain life. One way to figure out what is amiss is by looking at your plugs. Are they fouled? If so what has fouled them?
If there is a fuel foul you might want to install a fuel pressure gauge. See if your pressure is high, that is what my issue was. There is a huge possibility that your idle screws aren't set properly, "out of the box" means it is set to a stock situation, not set to your car. You are going to need to set up this carb for your car. My recent discovery was that the instructions included with Holley products are not as thorough as they used to be. There is a book called Super Tuning and Modifying Holley Carburetors by Dave Emanuel. It has a wealth of information on how these carbs work and you really would be doing yourself a favor by getting a copy. These books can be found at Advanced Auto and AutoZone. The Holley website is also filled with additional info on these carbs.
Other than that, I would say that you should probably gather as much info as you can on what you are experiencing. RPMs at idle, vacuum....
Why did you place a new carb on this engine? Was the engine running ok before you replaced the carb?