The rear and 727 in mine were removed from a 68 Charger with 2.94 gears. I have 3.23's in mine but the rear tires are 30" tall. If the Charger came factory with a 26" tire the difference in the gearing would be 24 points. (6 points of gear per 1 inch of tire) That would put me at 2.99 final ratio. According to the speedo which still has the correct speedo gear for the 2.94 in the transmission, I'm only off about a mph or so. Great for the highway but with a near bone stock 8-1 383 with a stock converter its a pig from a stop light. Average MPG is about 18 or 19.