500 yard.....BUTTERFLY!!!

After having a disappointing state meet and just a general lack of enthusiasm for the sport I took a couple weeks off of swimming and lifting to reset. I got it in my head that it would be really cool to swim a 500yd butterfly. Problem was is that my technique needed work and that even in practice I struggled to do even a 200fly. So I decided to just go a little at a time and really concentrate on technique and not worry about the clock. Started with doing aorund 2-400 then worked my way up to doing 1000 yards work of workout sets. just 25's, 50's and some 75's. After about 6-7 weeks of this I found that my stroke got a lot smoother and I could hold on for sets of 100's and even the occasional 200. Last week I decided to try to do a 300. It was a little slow but I saw the clock at 200 and I was right at 2:30 so my pace was pretty good..came in in under 4 minutes.. But what was really awesome was that even after the 300 I had enough in the tank to finish our workout doing half of it fly-about 2200 yards total! 2 days later at the other pool I swim at I told the coach about the workout and she knew that I wanted to do a 500 at the end of summer. She said why not at least try it now?? So I started out with a long kick off the walls for the first 200 and then it was just blood and guts from there. I concentrated at kept my stroke and glide really long and just let my mind focus on the task-not the pain!!! After 350 I got so excited about finishing I nearly choked after taking in a little water, but I regained my composure and kept going for it. At 450 I kept thinking "COME ON!! ALMOST GOT IT!!!" At 475 there was no stopping me now! At the end of 500 I was seeing spots!!! Finished in 7:10 No one arm, no hanging out on the walls, just a straight swim!! My splits per my coach on deck were 1:21, 1:31, 1:30, 1:32, 1:26. Now my next goal is to get this under 6mins by february 2013..maybe do it in a masters meet. I'm pretty much decided to abandon freestyle and work on getting through my entire workouts doing 80% butterfly. Any more tips and suggestions regarding this goal would be appreciated.