Got towed home yesterday need engine help

[Silverstreak02]

I took a long drive yesterday in the Cobra and it was running well until I was almost to the restaurant. As I pulled out from a stop sign it hesitated slightly and then smoothed out for another mile or so. At the next turn it bogged down pretty bad as I accelerated. I made it to the restaurant, but had to get towed home after that. It still runs, but idles roughly and the tachometer bounces between 600-900. Every few seconds the tachometer jumps to almost 2000 without any change in the idle. I have an Explorer motor with a Holley 570 and Max fire distributor. The setup has about 1800 miles and has worked perfectly until now. I've checked the following without seeing anything wrong.

1. I inspected the three and two pin connector at the Mallory Max fire.
2. I removed the cap and top cover of the distributor and inspected the cap, rotor and PCB.
3. Removed the tachometer signal wire at the distributor and started the engine. The tachometer still bounce some although the signal wire was disconnected. Power and ground was still connected.

The engine runs and idles, but it is rough although it smooths out for a few seconds every now and then. Does anyone have a suggestion of where I should look next? Thanks for the help.

Jeff