Ignition electrical issue. help?

Sounds like: 1) the voltage regulator has failed so as to command full alternator output; 2) there is a shorted brush in the alternator; 3) there is short on the field wire from the alternator to the VR, causing full field current; 4) there is a poor ground. Any of these would case full balls-out charging out of the alternator; that would explain the full charge deflection on the ammeter. Put the voltmeter across the battery and start the car. If the voltage goes above 14.4 or 14.5 V or so, and heads up to towards 15 volts or more as you raise the ilde RPM"s, then this is the case. The MSD is rated to work off of 18V but who knows what spikes the systems is seeing.

If you don't see this high voltage , then I would be thinking of a short in the main output of the alternator, that would cause the full ammeter deflection; that would be a serious situation. Because of this, don't be cruising around 'til you fix this.