CA to TN would be a rough trip. Figure gas to be $4/gallon and mileage to be around 10mpg. I personally would not reccomend driving a truck of unknown condition that far. I'm sure the seller has a tail light warranty on the truck. Once he can't see the tailights, the Waranty expires.
Can you explain the numbers matching thing to me? I just don't get why people go so crazy over numbers matching. Not only do the engine and transmission have to match for a numbers matching truck, but also the head(s), intake manifolds, exhaust manifolds, carbs, water pump, starter, generator. Many vehicles are mistakenly bought and sold for a premium as numbers matching, when they really don't stand up to the criteria.
