Hurricane IID had: different wing structure to support the 40mm cannon, additional armour around the engine, radiator and cockpit, plus the vast majority were used in North Africa so they also had the dust filter and survival gear.
It will be very slow(due to extra drag from 40mm guns and dust filter, and the extra weight of armour), doing only a little over 300mph at 18k.
Only 296 were made.
[ 08-15-2001: Message edited by: juzz ]