I'm inclined to agree with Wrenchbender Ret.
Your throttle blades are simply too far open at idle. Recheck the dwell just to make sure it's OK. Set the timing up a couple of degrees as Wrenchbender said. That should increase the rpm a little. Reset the idle speed screw to bring it back down, then reset the idle mixture. Good chance you'll have to reset the idle speed down again.
An idle solenoid is for a smog equipement burdened '70s engine or a small 4-cyl with not enough power to handle a AC pump at idle.
