Background Info: The engine idles reasonably well, (given the stage 3 cam), runs fine and temp is stable at 180F, even on hot days. Mixture nuts are set at about 2-3/4 turns each. My colortune shows my mixture to be about right, measured at plugs 2 & 5. Timing is set at 7 BTDC & carbs are balanced. Reading recent posts, I got "curious" and tried lifting the pins that raise the carb pistons. For both carbs, the engine stumbles badly... Not what it's supposed to do. Even when I increase mixture 1 full turn on the mixture nuts, it still stumbles. I do have the larger jet needles to accomodate the bored & stroked 2.7L L24. Question: So what do I believe? I'm inclined to think I should go with the color-tune results, but what do others think...