27.5 p middle notch on needle 340 mains... motor is in my sig... i was running 360 mains had color on plugs but wouldnt idle for shit.. had to keep in the throttle or it would die and foul plug.. running 340s it will fire right up and idle great, stutters a bit off the line screams and front tires off the ground 1/2 throttle , but stutters 3/4 throttle then i let out .. will do another plug chop tomorrow need to pick up some plugs went threw 4 sets with those 360 mains... any advice would be great.. ill post pics of the plugs once i pull them on the 340s.