What is making 2 cylinders fire and 2 not even when I switch coils pack still

What is your question?

Had blown head gasket so replaced that and had head machined, put all back together not no start, so checked for firing #1&3 firing but #2&4 is not changed the individual coil packs to #2&4 still no fire to those two its getting voltage to the coil packs but why is it not firing changed plugs too still no start