Personally, I'd advise taking it slightly slower on long runs. If you're doing the rest of your runs are at 6'30" pace, that's a hella drop. Not saying you shouldn't run it if it's comfortable, by all means do it if you're not feeling it too badly, but long runs shouldn't feel comparable to a tempo. This past summer I was running very similar paces, except my tempo runs were closer to 6 flat, as my runs had a lot of hills in them. One day I was with a faster friend and we hit 12 miles at 6:20 pace, nailed the last one sub 6. Now I'm not saying it was solely because of this, but it just so happened that a week later I found out I had a stress fracture in my femur. Did the run cause it? No. Did it likely contribute to/ignite it due to considerably unprecedented stress? Probably. When it comes to those types of runs, you need to build up to them, and it can take as little as 3 weeks to just progressively lower the pace of your long runs comfortably to that pace. Best of luck dude--if you're questioning it, I'd veer on the safe side. I was about to have an all-state season, but unfortunately it was cut short because I was reckless with lowering the pace of my runs too quickly over rather long distances. I forgot to mention earlier, but I was also capping at 60 over the Summer. Feel free to reach out with your email, I'd be glad to talk with someone who trains so similarly and provide advice on my injury.