Tom, I also heard that the 292 can be thirsty for fuel. I had a 454 in my truck that went south so I bought a used good runner. I was not expecting much but I went from 9 mpg to 13 right from the get go. I added a new HEI ignition and dumped the points. MPG went up. Replaced the cracked exhaust with a replacement manifold that had the large outlet and run a 2 1/2 exhaust with universal Borla muffler. MPG went up. Tried to get the factory carb to run smooth without a off idle bog, but failed.
It started leaking so I swapped on a 2 barrel autolite 2100 carb with an adapter from a 66 mustang. At that point my mileage jumped 2 mpg and power increased a fair amount by my butt dyno.
I now click 18 mpg on the nose after jetting with mostly highway driving. My truck tips the scale at 5200 pounds is 4x4 lifted 2 inches with 33 inch tall tires running threw a 4 speed. I have checked my figures several times with gps vs. gallons used so its not blowing smoke. Most unexpected, but I would not take "bad gas mileage" as written in stone.
