Replaced all 16 spark plugs with NGK 6509's, took 4 hours at a leisurely pace including ******** with the stock jack. Front two on the passenger side were a bitch to get the plug boot off, had to resort to garden-gnome sized lasso. Yippie kiy yay ************. Gear Wrench swivel spark plug socket and a couple extensions reached every plug with (relative) ease.