318 Magnum 70 Dart Gas mileage

Thanks for the info, yeah highway driving is my priority as i plan to be road-tripping in this car and i dont wanna have to stop for gas every 100 miles.
Oh I hear ya there!
No matter what, an intake and exhaust system that flows really well will allow the engine to work easier, make more power. Tune the carb well combined with a good ignition system, it will do really well in the Hwy.

Overdrives really help mileage but, that can be another venue to chase later. There is a sticky thread here on "How
To...." an OD trans into the A body.

My '03 Quadcab 4X4 Dakota with the V6 did well for the heavy underpowered tube it was. The OD trans really kept the rpm's down at Hwy. speeds. It had 3.55's for gears. And a dang tall tire. (Stock for the truck but really tall next to a car tire.)