Sub 3.30 pacing for London

[Deleted User]

Just wondered what peoples thought/ideas are on pacing for London ,my idea after recently running a 20 mile race with a big negative split is to run the first 10 at 8 min mile pace then next 10 at 7.40 , leaving me around 53 mins for the final 10k ,the 20 mile race I did I ran the first half at 8.15 and the second half at 7.45 and this worked pretty well