I have to dis-agree with the fuel mileage. My 292 in my '64 C-30 fully loaded at 10,000 lbs would get about 14 MPG and that was just with a 4-Speed. I know that is better than average tho as most people I talked to didn't get quite that good. But if you super tune a 292 and drive it correctly (including shifting it at the right RPM's) it will do real good. I just about never had it to the floor and I used to climb some steep hills. What I could do with a 4X3!!
Bill