Are you using all OEM ignition components? Any aftermarket bits are garbage. ICMs especially, Blow Reilly's will sell you the same POS for a 93-97 LT1 and GM spec'd 3 different ICMs: 93, 94-95, 96-97. They all have different curves and none of them match the aftermarket stuff from what I've read. Now an ICM is more of an item that either works or it doesn't, so doubtful it's the smoking gun for this but I am inclined to leaning toward wiring or electrical/engine management if the compression is solid. We had an LT1 here that also had a bad pigtail for the coil so the car would just randomly die and gave no indication on the scanner WTF was going on.