Help with a miss and voltage drop

Ok still missing. I have now tried a new Alternator, no change. Along with new ICM, new eCoil. I checked out dizzy for worn or exposed wires...nothing. I also just took car to Oreillys and had them come out with there machine and run tests on charging system etc... nothing wrong. If anything he said it seemed a little high like 15. Which is strange because in my car I have a volt gauge and it only says 14.3 - 14.7. Never 15. He also said battery is fine.
I also removed each spark plug, they all look the same, nice and tan. I also removed each wire while it was running and they are all getting spark.
where to next? my gaps are at 45 since I am running HEI. do you think that is too much and could cause misses??