Mileage Maker

[Indyuke]

Originally Posted by 1972RedNeck

The NV4500 has a .73:1 overdrive. Would 4.10 or 3.73:1 rear end gears be better. The 292 has a lot of low end torque as it is.

What would the max safe boost be? 7 Lbs.?

A 292 isn't going to give you much by way of fuel economy. I believe they are on par with the average SBC. If you went with a 250, your fuel economy would be noticeably better. Turbo or supercharging any motor will actually give you worse fuel economy overall. The only reason Ford does it with their new ecoboost motor is so they can get away with putting a dinky V6 in a full-sized truck while still tapping into the power of a V8 when you want to. But when that turbo kicks in, fuel economy goes down the drain.

If you want fuel economy, a 250 I6, NV4500 and 3.73 rear gearing would give you the best options. Good fuel economy overall, but still able to haul around a full load without too much hassle. I imagine you'd see high teens mixed city and highway driving with that setup.