i have a stroker 340 that recently developed a rough idle and low speed stumble. i believe it is a fuel delivery issue after troubleshooting. part of the troubleshooting had me swap the holley avenger carb i had for an edelbrock performer carb that i used on another engine. the stumble is about the same but i found 2 things, i had a vacuum leak in the pcv system that is now fixed. this did seem to help a bit. the second issue i found was at idle the edelbrock seemed to be dripping fuel from the accelerator pump, more on one side than the other. i am pretty sure there should not be any fuel being drawn from the accelerator pump at idle. i set the floats so i am pretty certain they are accurate. also i checked fuel pressure and it is steady at just under 7 psi. i know edelbrocks like less than this so maybe that is the only issue.
one other thing that i noticed is that it seems to pop out of the exhaust when i manually downshift into second from a higher speed. i'm not sure if this indicates it is rich or lean.
any suggestions?

i'd try float levels first. added fuel pressure has the "effect" of raising float levels, especially if the pressure is in the marginal zone. try dropping the levels about 1/16" below spec for a starter.

Try lowering the fuel pressure to 5.5 max.