Alloytech misfire

[Johnathan1111]

Hi guys, I just fixed a head gasket on my 2006 Holden ve alloytech, ran good until it heated up over halfway but not all the way then started misfiring on one side, I changed the cam sensors and spark plugs and coils then it runs good but it still gets hot but doe sent misfire anymore, I checked the wiring everything looks okay the only thing I can think about is the cat when it warms up besides that does anyone know anything else it could be ?

 

[Fu Manchu]

Because it's a bit on topic for me, where did you get the plugs?