Since you put a kit in ,you may have gotten the power valve gasket wedged in and not letting the PV seat properly. Happened after the Stepson opened up his Holley. i noticed the PV was not as close to the metering block as it should be.
The first question to ask when troubleshooting is "what did you work on last?" Gets some strange looks but is a usually a shortcut to the problem
Hope I helped,
Ron

In sixty-five I was seventeen and running up one-o-one I don't know where I'm running now, I'm just running on Jackson Browne-Running On Empty