Of the A330 performance I have no knowledge but I have spent the last 20 years flying 767 aircraft on longhaul operations out of many UK airports including LBA.On an ISA standard day still air using optimised flap with packs off the 763 is limited to 167.4 tonnes on RW32 and 172.5 t on RW14.This is a long way short of the max. structural regulated take off weight of 186.8t.Typically zero fuel weights will be around 120t, depending on atlantic winds I,d expect a min. fuel required to Florida or the Caribbean to be 46.0-50.0tonne .Direct flight capability will always be an on the day decision.Shannon has a long runway and has saved the day on many occasions for a quick fuelling stop.My personal record is 26 minutes from Brake on to Brakes off for a transatlantic fuelling stop.The reduction in seating capacity of 767s with the increasing popularity of premium seating has helped a little with the range capability of 763 aircraft from limiting runway such as BOH,BRS and LBA .Regards Stampe