I havn't bought my first old truck yet, but am planning to buy a chevy advanced Design soon. I don't know much about engines so I thought I'd ask the pros. I want the truck as a daily driver, and also to do light farm work. I'm looking for the best possible gas mileage, ability to cruise at highway speeds, and enough power to haul a 1/2 ton load without a problem. Any suggestions on the type of engine I should look for? Also what about gearing and tranny? Appreciate any help I can get.