It's been a long journey tuning this thing but I'm finally at a point where it feels like I'm making progress. Things I changed this year was an aluminum rad and one step colder plugs, but one thing that made the biggest difference so far was adding an octane booster to my tank of fuel. A local shop had this lucas 3x octane booster, so I did some research on it and it seemed to have good reviews. So I tried it and what a difference it's made. 91 octane by itself seems to cause tuning woes. Engine is 10.2:1 with aluminum heads, I could never hear if it was detonating and I'm not to experienced in plug reading. Prior to the lucas additive I idled at 13.4, cruise 13.8. Any leaner on either setting and it would drive like crap. Granted I have a manual trans car and the system apparently isn't suppose to work well with stick cars. Not sure where or how this would show itself to be a problem, but one super annoying thing it would do was in between shifts when you get back on the gas it would have a complete lean dead spot before recovering. Kind of like not having enough pump shot on a carb when mashing the throttle. But this was under normal throttle movements where no amount of accel fuel had an effect. Fast forward to adding this additive in the fuel, so far I currently have my idle and cruise fuel at 14.0 and 14.1 and it's working very well. I feel it can go more yet, but I'm working up slowly giving it several trips between adjustments. As for lean flat spots between shifts they are almost non existent. From time to time there's an ever so faint hint of it. If I had to pick an area to improve on it would be off idle transitioning. There's a little bit of a blubber on tip in which could be just a cam shaft gremlin. At slower engine speeds it doesn't have a very clean off idle transition. I took a couple pics of one of the plugs, other than the color probably from the additive, is there clues as to the state of the current tune?