340 Chugging instead of Reving

I noticed that while none of the plugs look great, the odd bank plugs seem noticeably darker. Seems odd, maybe just me. I was going to suggest a different set, or even a different brand. I had more of a high speed miss once. Changed out all my ignition parts before the plugs. Wound up being the plugs. Had switched from Champion to NGK. Put my old Champions in and guess what? Yep. I would have never thought either. Now with that being said, I use NGK plugs yet. Champion quality seems to be in the shitter these days.