Idle problem

Might want to check the gap between the reluctor and magnetic pickup coil in the distributor too.

Agree with dropping the idle speed if everything checks out. I have a six pack setup (six idle mixture screws) and lopey cam that idles at 750 in park. Slowly back the idle down to close to stalling while adjusting the idle mixture screws. It should idle lower if no other problems are found. Like Moper says, sounds like you're out of the idle circuit at that RPM.