You can't really drop your aerobic pace. It has to drop itself. The more time you spend running at your aerobic pace the more it will drop itself because you're spending more time doing the work.
That said, there obviously are points of diminishing returns. The OP obviously is not looking to do really long runs and big miles so I'm not pushing him to 90-120 minute runs. But if you're doing 5-7 mile runs and you're hoping to do them at 6:00 pace (just grabbing numbers here) I think you'll get to that 6:00 pace faster by getting to the distance and letting the pace come down because you're spending more time with your heart rate up etc. and getting in more training than if you're running say, two miles in 12:00 and hoping to extend the distance.
Trying to get Lydiard or anyone who learned from him to give specific paces for distance runs is like trying to get a politician that everyone thinks is running for president to say definitively that he's running for president. It's all done at perceived effort except in very specific circumstances.
Snell told me that he knew when he was doing his distance runs too fast because he'd be too sore and/or tired the next day to do the run he was supposed to do. From that perspective you would do the runs as fast as you want as long as you can repeat the effort the next day and the day after, etc. Or you'd use Lydiard's method of running an out and back course where the altitude of the turn around point is about the same as that of the starting point. You should be able to run the "back" part in pretty much the same time as you ran "out" without increasing the effort.