I sure learned a lot reading through this forum, and I appreciate all the responses to my questions, especially the great diagrams on my transmission question. After a summer-long search, I found on an 07 GMC Sierra Classic four-door extended cab Z71 with the 5.3 and the 3.42 transmission. It had 113,000 miles on it and came with nerf bars and vent shades installed. I'm ok with the color; I would have preferred the bluer gray but this truck had what I wanted at a fairly decent price, so there it is. All I've done so far is temporarily stick my cap on it so we could go camping, and put on a mossy oak steering wheel cover.
I've put a thousand miles on it so far; hauled my little utility trailer loaded with kayaks through some of the two tracks in the Mack Lake recreation area, and made two trips all the way down to Lansing for meetings. So far so good, no problems aside from fumbling with some dash buttons that are different from my old Silverado.
I did notice a blue cloud out of the exhaust when I grabbed some power to pass someone while I was pulling the trailer, but haven't had it happen since. I do wish the seat had the six way power like my old truck, instead of the the strange hybrid seat with up and down, back and forth power, but manual seat back, and I don't like the radio controls nearly so much. But I'm really digging the driver's side back door, the larger back seat area, and all the fancy things like heated mirrors and can't wait to hit the dunes and try out the 4x4. The best mileage so far is 17.8; sure miss the 22 I got with the old 5.7.
There is a significant amount of road noise and the BF Goodrich tires it came with have worn in a chopped pattern I've heard is common to these 4x4s; not sure what to think of that but I'm planning to put a set of Coopers on it soon and really hope that diminishes the noise, it gives me a headache on longer trips.
Anyways, didn't mean to run on so, just wanted to let you know I appreciate all the great info here.
P.S. Anyone looking for a 15 year old Silverado with 300,000 miles on it?

![Firing on 3 cylinders [L1] Firing on 3 cylinders [L1]](./images/ranks/sparkplugs/ranks_sparkplugs_3of8.gif)
![Combustion on 2 pistons [L2] Combustion on 2 pistons [L2]](./images/ranks/pistons/ranks_pistons_2of8.gif)

![Combustion on 4 pistons [L2] Combustion on 4 pistons [L2]](./images/ranks/pistons/ranks_pistons_4of8.gif)

![Shifting into Sixth Gear! [L3] Shifting into Sixth Gear! [L3]](./images/ranks/shifter/ranks_shifter_9of9.gif)

![Shifting into Fifth Gear [L3] Shifting into Fifth Gear [L3]](./images/ranks/shifter/ranks_shifter_5of9.gif)


![Combustion on 8 pistons [L2] Combustion on 8 pistons [L2]](./images/ranks/pistons/ranks_pistons_8of8.gif)
![Combustion on 7 pistons [L2] Combustion on 7 pistons [L2]](./images/ranks/pistons/ranks_pistons_7of8.gif)
