Kinda OT, but skywalker... on highway trucks do indeed have emissions standards to meet nowadays. We just had a bunch of engines in our shop that were manufactured earlier this year that we couldn't sell because they did not meet emissions. To put them in a truck, special aftercoolers and (get this) catalytic converters had to be fitted to make them legal. Not to mention special actions taken by OEM's lately to reduce NOx and particulate emissions via cooled EGR and compound turbocharging. And most all on highway engines and a lot of off highway engines have gone to electronic control of fueling and burn a lot cleaner than the old mechanical engines, even at full load. There's all kinds of cool tricks a tech can do on the electronic controlled engines. Kinda kin to going from carb to EFI on a gasoline engine. Just thought I'd throw that out there. -Chuck