Very nice truck, however to get the kind of money your asking you have to find the right buyer. That can sometimes take time. If you want to maximize your money, put it as back to stock as you can(pull the twins, the monster pump, injectors). I think the tires/wheels on there will help the sale, as it will catch attention and looks great. I am guessing you know this all already, just sometimes helps to hear it from someone else.
FYI in fall of 2011 I sold a 2001.5 HO quad cab 4x4 SLT. One owner, very clean, only rust on it was in the door seams, under 55K miles, got $17.5K for it. Took me 3 months to sell it for that, several offers for $15K, but I felt it was worth more.