Or if 180 out , plug wire at #6 becomes #1 at dist.cap and reroute rest of plug wires , if it starts you were on exhaust stroke and not compression stroke, but your preload on lifters may also be to tight as Schurkey suggested. Also wouldn't be first spark plug wire routing that I've seen because of being 180 out. It will run just fine but not where GM intended it to be.