The only way you will get 18k is if you sell it to someone that has a clue what you have in it, and what they don't need to do to it. Otherwise your looking at about 14K even with your mods. Most people don't care what you've done to make it faster. They just want it to be reliable. I agree if you had all the old parts you would get more buy selling them seperate. There is a guy on here with basically the same truck for 16k. His is stock, but he only has 30,000 miles.