Just know that those 230's are 4000 rpm motors. Peak 125 HP at 4000 RPM and about 230 pound feet of torque at 1000-1200. Putting a bigger carb does not mean it will get worse mileage. I'd bolt on a 2 barrel and a nice set of headers and you'll get better mileage that way( and a little more power). I have a 600 cfm edelbrock 4 barrel and headers on my 292 and it gets better mileage simply cause its not starving for fuel. I also have an HEI on it as well. You can check out my build for more info(link below). As said a TH350 auto would help alot...also another good choice would be a richmond non-od 5 speed. Gives you 5 close ratio gears which would help in down shifting..and I will repeat, This isn't an OD trans.
