I have a 68' pretty close to yours with the exception of a Comp Cam that operates @ 2200rpm. What I did this winter was change the 2:79's to 3:25's. I wanted better low end and I think this will help, I'm a little afraid of the gas mileage when spring finally gets here in the north east and we can get back on the road.
Rich
68' LIme Gold Coupe
Rich
68' LIme Gold Coupe