if it was enough to cover a diesel swap, Id got 4BT in a HEARTBEAT!
otherwise, a big block (383/400/400) built conservatively with good low end torque and 3.21 to 2.76 gears would be OK enough to get you into the high teen's..
There was a guy either here or on RCC, that had a 4BT in a 74-75 Ramcharger and claimed to get 30MPG Highway/25MPG City.
The Federal Government has not yet learned that you cannot legislate morality
1970 Coronet R/T FF4/FF8/V85/V1G 440/Auto/3.23
1970 Coronet R/T FK5/FK5/V8W/V1W 440/Auto/3.55
1970 Super Bee TX9/TX9/V8W/N96 383/Auto/3.91
1975 Duster 360 VS29L5 Daily Driver
