I recently got my wife's 74 Ramcharger running & driving again after sitting for too long.

It's a factory 440 truck and the only mods are an intake off of a 71 440-4speed car, heat crossovers blocked off, double roller timing chain and melling HV oil pump. I'ts got D60/D70 axles with 3.54 gears and 33" tires on aluminum wheels. I've driven it 255 miles now and using the Fuelly App to track everything, I'm getting 6.7mpg average. Currently having to leave the hub's locked as I have not installed the MM 203 Part Time kit yet.

I drive it to Mustang Island / Port Aranas to cruise, eat, drink, get sunburnt and back. going 63mph on the highway I'm turning 2100rpm.