Idling Issues - Holley Carburetor

Yeah, make sure the choke is off, the secondaries are fully closed, the pcv is functioning, the brake booster hose is on or plugged,the primary is closing to the curb,the vacuum advance is not engaged, and the T-port is synced.
If you still have problems, it may be a a vacuum leak, or a low-speed carb issue;assuming the timing was not changed during the install.