if you want better gas milage , don't go down in motor size , go up to a 305 or 350 . you have to remember these vans are like a big brick on the road ,not very aerodynamic.by down sizing the motor your making a smaller motor push the same weight as the 4.3 was , theres no way your going to get better milage . now if you drop in a bigger motor you now have more HP & torque to push that little van along the road . increase in milage is inevetable as long as your not hotrodding all the time . :layrubber: