Recommended 4bbl carb for stock 318

At the tail end of the years when American cars were big boats (1977) I worked at a Buick dealer. The ole Electra 225's and Park Avenue's with Quadrajet powered 455's would get late teens, almost 20 mpg highway. It can be done. Those old engines had more torque at idle thatmost engines have nowdays at 5000 rpm. LOL
My Dad bought a nice used 64LeSabre, that I got to drive after I got my lecense, in 69. It had a 401 torque monster. I dunno what it had for a convertor but dang that was smooth. One day we were on a family outing and I got to drive! A short time after we settled into the trip, Dad leans over and says something like " are you in a hurry to get to Grandma's house?" I looked down and saw that I was speeding big time.