Possible slop in the dizzy or timing light errors. Maybe move your trigger pickup closer to the cap/rotor to rule out delay caused by high resistance in the wire
Ok thanks. Good info. I'll try setting it at 2,000rpm. By 'dizzy' , do you mean distributor? The distributor does seem sloppy even though it's new. Especially the up/down movement. But it is no different than the one I replaced it with.