well my friend has a montecarlo with an edelbrock performer manifold and the stock qjet carb. will a holley dp match up to the manifold?

Some will, some won't.

What list # is the Holley?

It'll match up. Performer manifold is dual-drilled for a Holley bolt pattern. However, you will need the correct gasket and the metal plate that holds the gasket from falling into the manfiold where there might be a slight gap on the sides at the back of the carb. It goes GASKET, metal plate, GASKET.