In reply to mbh:
Cheers, I am well chuffed with that time. Apart from 200m at the bottom where I was eating a hot cross bun I managed to run all the way up the 6 mile long hill up over the beacons.
One thing that worked a treat was when I got to about 32miles I wasn't sure I could run continuously so to keep a bit back I did a strict run 2min, walk 2min. That really kept the momentum going and I was managing 11min miles even doing that. Chips and coffee at the last check point got me running properly again and I think I ran the last 6 at about 8.5 min miles.