70 Duster with a 408. Had 3.23’s when I had the 340 in it, switched to 3.73’s when the 408 went in. 245/60-15 tires. 3.73’s are a LOT of fun in town, but I was going into 2nd before I could out of an intersection. And interstate I was not comfortable going very far. Put the 3.23’s back in. Way better for daily driving, (3000ish rpm @ 70 mph), and still can light them up if I want to