SB Advice.

I'm just gnna get straight to the advice I need. I've got a 73 Duster. There's a 318 that's sat for 18 years but still runs like a champ. There's a guy at my church that has a 76 dodge 3/4 ton with a 360 that he's willing to give me the engine if I put in my 318 in his truck for him. The 360 turns over but I have yet to here it run. So here's where I need the advice. I wanna be able to drive my duster whenever I want and wherever I want. So in other words I want it to be more the just a weekend driver. Yet I don't want to break the wallet to bad on the cost on gas. Yet to be able to the power to easily get up and go. What would you guys do?