The last couple of printed TDR mags have talked about an aftermarket fuel tank to replace the original, and give a total capacity of over 50 gallons. That would sure make towing long distances a lot easier. Anyone have any experience with these tanks? About how much $ should I expect to spend, including installation? Does the spare tire still fit under the truck? How about tire sizes that are larger than stock? (I have 285s, will that work?). Thanks in advance for your words of wisdom!