I have installed the Holley Sniper 2300 on a Toyota 2F (basically a clone of a mid fifties Stovebolt). I'm really happy with the installation. Driveability is a 100% improvement over the weird Aisin two barrel. I don't expect much improvement in gas mileage, if any. Can't fight physics, it still takes the same amount of BTUs to move two tons of stuff down the road. I just like the "get in it and turn the key and go" aspect of the whole deal.
SimS