Possibly. Is this how it's been since the new/reconfigured engine was started, or is this a change in behavior from when you first got it back?
If it's been this way, it's possible jetting is wrong. And maybe it needs a synch/tune.
If this is a change, it's probably a plugged idle jet.
Either way, have you dumped the oil and adjusted the valves since the new heads were installed. Re-torqued the heads?