I do assure you my my Powerstroke 7.3 is in tip top running order its got 4:88 gears and 6 speed so it's a stump puller not a fuel saver. The 7.3 and the 6.0 (gasser) are two diffrent animals and like you said the 6.0 does well for what it is. It will do the same job as my 7.3 it's just going to do it at a slightly higer rpm. Here's how I see it about gas vs diesel you either want a diesel or need a diesel. I got my diesel because of its higer GVWR.