I have been reviewing this posting and am a little tired of reading all of the negativity on the 6. 7L. I am a very happy owner of a 6. 7L truck. I read the posts under the 6. 7L forum and know of the problems people are seeing, but there are many of us very happy with our trucks. I use my truck as a daily driver and have never towed a trailier of any size.
My suggestion, read through the 6. 7L forum and find the tricks people are using to be successful with their trucks. It is possible to have a good running truck. You will never get a gas truck with anything close to our MPG with the same size and power.