63 Dart big problems

I thought it was my ignition was causing a miss, well after chasing it down for a week, my neightbor came over , another slant 6 guy. we pulled the plug wires off 1 at a time, and # 1 didn't change. Put on a new plug wire, still the same. Neightbor says maybe head or piston skirt, Will do a compression test next, any thoughts , the engine has 70K miles on it, thanks Jim.