Drafthorse-
You said you know nothing about trucks but you are on the right site! With that said, I recommend you get the V10. If you are not a truck person, the gas is much easier in maintenance and operation. Then toss in the increased purchase price and increased $$ per fill up and the V10 looks like a steal! My wife had a Diesel Jetta and we just got rid of it (back to gas, still a turbo) due to fuel costs. Now I can get gas at 2.39 while diesel is still at 2.89-2.99. That fuel cost eats away all the savings of the diesel. We bought the car when diesel was cheaper than gas and the motor was selling at a discount, not the case now. Good luck!

V10DoubleTow-
3.73s and 35s and still towing that load? How much decrease did you notice towing all that weight? I have been ridiculed before for not changing gears when I lifted my X. I have a V10 with 6inches lift and 35s and still the 3.73 gearing. I was told that the tranny would not last with these changes but she has been great. I will say that I do not tow much and like driving fast so the increased tire size allow me to run 90 at just over 2000 rpms. My Bronco had 3.43s and 35s and this is much better than that which is all I have to compare it to.