I agree with Stock87...

Put factory original parts in it... It's well known that a number of aftermarket O2 sensors don't match the exact length of the factory O2 sensor and they aren't centered properly in the exhaust stream...

and I especially like NGK plugs.. excellent performance and one other thing that even the ND plugs don't have.. The threads of NGK plugs have a plating over the steel base metal that keeps them from seizing up or making the horrible, scary squalking noises as you try to remove them after they have been in the head for a long time.... especially important in aluminum heads...