Tonight I was working on my 1973 Plymouth Duster with a 318, originally this duster had a 225 slant six but the original owner blew up the engine do to the point they forgot the oil. So the owner had her sons put a 318(year of engine is own know) but we know it came out of another duster. Tonight I was looking at the carb set up and notice that I was running a single barrel carb. Is this stock? Like did Mopar make a V8 with a single barrel and why? Also, if it is stock how common is it for there to be a stock 318 with a stock single barrel carb??