Cold Start Rough Idle

[El Supracabras]

Yes, the gte uses a wasted spark ignition. The ge uses one coil connected to a distributor cap. I know 1 and 6 share a coil but dont remember the order of the rest. Its posted in numerous places. There are tests to determine a bad coil in the tsrm. You can sometimes spot tiny cracks in the plastic and epoxy on them if you just take them off and look closely at them. I've even seen the plastic surrounding the connector terminal crack and corrode inside causing intermittent misfires.
Have you checked the timing? I've noticed on many cars that prior owners/mechanics will adjust the timing to mask other problems (vacuum leaks, tune up, bad sensors,etc.), so when you start fixing those problems the timing sometimes winds up needing adjustment. My opinion is, it's always a good idea (though not always necessary) to check timing after repairing things relevant to drivability issues. Try checking it, it's free and who knows, you might get lucky.