360 or 440 for my 1970 dart daily driver

Thank you for all of the wisdom but im a very good driver for my age and have been driving since ive been physically able to im not jus some dumb 16 yr old trying to go fast without a care in the world. If im racing its in a more controlled envrironment. Not 2 in the afternoon on a busy street. Thats all im going to say about that. Not trying to be disrespectful in an manner whatsoever but i jus want some answers as far as what i should do to my car to make it reliable, fast , and make decent mileage