hmmm...guess i shouldn't say for sure. i know mine got awesome mileage, but it was a 2wd with the 3.08 rear end. on the highway though, it was breathing hard to do 130+...not that i pushed it like that much!! i could see the 351 in the given truck(lifted, bigger rubber, etc) getting a bit better than the 300, but i shouldn't say for sure. i guess we'll have to wait to hear from the hunter.