When I decided on a 366 I liked the idea of the torque, the sound and i was hoping due to its small bore.. perhaps reasonable fuel mileage, it is in a 86 c10 with a 700r4 and overdrive, 3.08 gears and i drive so slow its crazy.. and im getting 50 km per 15 l of fuel.. this seems horrible.. i think im having some lifter/cam issues.. but with a q-jet, ver mild fresh cam.. minor porting of everything and super mild driving is it possible for 18 mpg average?? or am I totally barking up the wrong tree? Please opinions are welcome.