After head gasket replacement, timing belt OK and aligned, compression OK, fuel OK, engine cranks but will not fire, back fire or any symptoms of ignition. Poured gasoline thru carb, plugs still dry after trying to start. Blowing air thru cylinder to prove flow thru carb. Still won't start. Timing light attached to No. 1 firing on top dead center, still won't start. Sprayed either in carb also. Still won't start. HELP!!!!!