well i'm new here ..... someone mentioned lifting the flap inside the wheel well to get at the #3 spark plug -- that is the way i've seen most gm techs do it and is also how i do it - i just use a 5/8 spark plug socket followed by a swivel ( or knuckle ) then a couple of 3 inch extentions on a 3/8 ratchet - its really crampped in there for big hands but it does work - and might as well do number 5 plug while you are there .