Need the spark plug torque specs for 2001 GMC Yukon XL with 5.3L V8

15 ft lbs.

Really you can snug these down with a common ratchet without harm. Make sure on these engines that you are using only the AC Delco spark plugs. If not you can trigger a check engine light with a P0300 random misfire code. If you are concerned about siezing, use a light coat of antisieze on the threads of the spark plugs. The book calls for 11 ft lbs but in my 20 plus yrs, this is not enough and will work loose causing performance issues and possible damage.