tach problems

Ignition module is failing. It's located on the front of the intake manifold with wires coming out of both ends...replace and all is well.

181 is system lean

Check fuel pressure regulator. Take a look at the regulator and make sure the vacuum line feeding into the top is connected and in good condition. You were just in that neighborhood replacing the ignition module, you could have pulled it loose or aggravated a dry-rotted vacuum line.

Check Throttle Position Sensor. - there's some great info on testing and setting TPS's around here if you search for it.

Go back and check everything in and around the area you were working. It didn't run this bad before you did the module swap I'm assuming, so it's possible the problem lies there. Not the module itself, but the surrounding area. The more I think about this it sounds like a vacuum leak.