Well since you love your converter and I dont blame you. You will want to maintain your engine rpm above the converter stall so that you are properly connected to the ground in order to get decent mileage. So, I guess if you either move 3" taller rear tire or change gears to taller and still maintain cruise speeds above stall speed, this would mean you are traveling further for the same revs.
Seems like you would want your target cruise rpm to be 3k to 3.1k.
I agree with everyone here, just throwing out my two cents.
I also agree that you may have better mileage left on the table with your existing build. Maybe a careful timing scheme with some vacuum advance, jetting changes too.
There is a very well thought out and nicely explained timing tuning plan posted in this thread by jbc426 which entails using manifold vacuum which is supposed to enhance cruise mileage and part throttle torque. He explains that there is a symbiosis to initial, total, curve rate, vac can choice and settings which would likely require a lot of patience, bit of fab and a good level of skill. I am giving it a solid effort to duplicate his recommendations in the near future.
http://www.forabodiesonly.com/mopar/showthread.php?t=278252