CTKGP09, I used whatever expensive platinum plug the parts guy was pushing. I thought platinum and more expensive would be better. Should have gone with OEM. Changing the rear plugs was definitely a chore. Removing the front motor mounts and putting it in gear and torquing the motor forward. Even then it wasn't easy. What would I look for with leaking LIM gasket? Oil leak? - thanks to both you and Seachicken for the responses.