Half coil failure
WX has been 30 or more degrees cooler than average for INDY for the past month, some days the high has been below "0". For that reason it took nearly 3 weeks before I could flight test with the new coil and the new wire. It ran perfect!
Prior to this I often saw a rise in EGT on cylinder 4, it would come and go. I did not worry too much about it because the CHT was always well within range. The EGT rise was likely caused by intermittent failure of the coils out put to plug/wire #4. It took a complete failure of this half of the coil to make it apparent that was causing the problem. The problem is now solved.