I drive my Roadrunner as much as possible, weather permitting. Although I do drive in the ice and snow,winter in New England much to the horror of some of my friends who believe there cars are made of sugar! But with 4.10s and 28 inch 275/60R15s I rarely go on the highway for more than 20 miles at a time. Fuel prices being what they are I've been driving the Roadrunner more because of the price of diesel for my ram . I see someone is selling a 42RH here for 3400 or so. That with maybe a 5.2 Magnum
(cause the stroke on a 5.9 just eats fuel) in an light A body with cushy seats, a kicking sound system and A/C should cover it. 3.23 gears. It might be cheaper to by a 5.2 drivetrain from an early 90s B van. Save the money on the drivetrain and do up a nice body. Although I don't know what your budget is.