I'm getting a car with a truck 2.6 and a narrowblock 3 speed without overdrive. It has the 3.54 rear end. I'd rather keep the A904 and get another ring and pinion. Was there ever another option for a rear end that will fit with a more favorable ratio for MPG? Either Mitsubishi or aftermarket. Engine is turning at about 3000 at freeway cruising speeds -- a bit too high for an old girl like this Colt.