Hmm, reason I asked was because Bow has a current allocation of @98 and according to VOSA a capacity of 110 (Thats discs rather than physical), West Ham, is listed as 255, with a current allocation of @120. Obviously VOSA 'vehicle maxs' can be changed. Leyton, the other obvious site, seems to be at (theoretical) max capacity too.
I don't pretend to know the actual physical parking space available, seem to remember that when it opened, West Ham was described as the largest Bus Depot in UK, probably overtaken by Firsts Caledonia depot in Glasgow at @ the 470 mark!