1983 Oldsmobile 88 Brake line replacements

I have a 1983 delta88 royal I have replace some of the brake lines and don't have any leaks . I bled the brakes but have had no luck making them work. My question is what size line should I run under the car or all around . How do I bleed the brakes so that I have no air in lines . Thank u for your time hope to hear from you soon