Like said, don't be in a hurry to swap it out.
Nobody that installs a 4.10 rear end is thinking much about mpgs. and after the 292 went in, mpgs became a distant,foggy memory,of something he thought he once knew something about.
292&4.10s pretty much means city-car/race-car, and these are like my cat with an open food-bag; she consumes for the joy of consumption.
I only kept that 292 for one summer, then I chalked it up to learning, and when a young unmarried man I had taken for a ride heard it was for sale, I let him have it,Pow. And one day maybe two summers later,when I asked him about it, he was still loving it.
I never took that combo on a road trip, so have no idea of it's potential to make mileage, but as a city-car it could burn a tankful in an evening, so Ima guessing it mighta made 120 to140miles in 4 to 6 hours. I'd call that right around 8mpgs with the Holley. I didn't run it very long with the TQ, and I love TQs!
AJ's Quest for the Funnest Street 360-4spd Combo;short version
