I swapped out my accel u-groove spark plugs for a new set of NGK-TR55's gapped at .045. Took me approximately 5 hours to swap everything and man what a PITA. #5 and #7 were the worst. The job was much easier with the ORYP, BBK headers, A/C delete, and starter removed. I had to modify a 5/8 spark plug socket and chopped almost half of it off. The old plugs all looked normal however the wear on the electrodes was very bad and the breakdown led to a gap of .055-.065. They only had about 45-50k miles but I guess thats normal without the platinum tips.