Boy does that bring back childhood memories. My folks had a 72 1010 2wd Travelall we used to tow a tag camping trailer with. It had the 392 in it and a tow package. Best it would do was 10-12 mpg, but could have towed 2 trailers!
If my choices are the 360 or 440 I'd stroke the small block and keep the cam timing relatively conservative like an XE260 or XE268 or maybe the 450/455 lift purple cam. You wouldn't want much over 9 to 1 compression as cylinder pressure would be pretty high with a stroker. A magnum 360 with or even without the 4" crank would be a nice choice. Overdrive trans and it might not be that bad on gas.
Keep us posted on your decision!