Does your alternator warning lamp ever flicker or come on at idle?
What does your system Voltage read with an analog multimeter at idle, and above 2000 rpm, and is there any 'dancing' of the analog Voltmeter reading at idle?
If the Voltsge regulator is ald and contacts are pitted ... it may be causing the problem, but so can worn brushes ...
If Voltage dropouts are occuring, I suggest installing a 5 Watt 68 Ohm resistor in parallel with the alternator warning lamp bulb -- just solder it right to the bulb holder terminals. The resistor will lower the 'Zero-Ampere alternator rpm' that can cause the warning lamp at idle speeds.
There is no such thing as an MFI-miss! You have ignition problems, not MFI problems! Have you removed your distributor and cleaned it, and checked for excessive bushing wear and play in the distributor shaft? Worn bushings can cause a 'timing scatter' that optical triggers won't cure!!! And, apparently your Crane trigger 'upgrade' gave no improvements at all!
Read the following thread and do ALL of the checks!
http://forums.pelicanparts.com/showthread.php?threadid=5432&highlight=distributor+lube