IS A NIGHTMARE HAHA!! Man I bought that thing in 2010 feeling like I was the champ getting a truck that slipped down to 6 cylinders on the highway to save fuel. Took care of it for all I was worth. Change the order every 3500 miles even though GM says 7500. Kept up on everything religiously. Drive it like my 90 year old grandpa. 5 years and 136,000 later the rear lifter in the shut off cylinder goes and ruins the cam as well. $3-$4000 to repair and there are 15 other lifters in the engine to go. When will the next one go? Replace them all......$5000ish. So I decided to just drop a new engine in the thing for $6400. Oh by the way, this is nearly twice the cost of a normal V8 remanufactured engine. The point of this post is to not talk people out of the Vortec but just consider the daul stage engine as a small risk. If something goes bad it's gonna cost you no matter what. Those cylinders kicking on and off all the time wears them out way faster then the other 6 that are just on all the time. And replacement of the motor is a lot more expensive than a standard. The money I've saved in fuel mileage is more then gone with this issue. I love Chevy Silverado's but I will personally never buy a dual stage engine again as much as it pains me. This is actually a 'quiet' common problem with Silverados.