Hi Aer Lingus, Buzz here. I'll have to look on the computer at work, let you know early next week. I don't really know the 777 very well since they don't come to PDX.
We have a couple versions of the Bigfoot (ever seen their 6 wheel main gear on final aproach?) One version has a higher takeoff weight than the other, and has "stronger" engines.
Engine intemix is not unusual, we make sure the stonger engine matches the 'normal' engine so the pilots don't fly in circles.
And since we use our Bigfoots for ETOPS work, we're really careful about making sure there are few unpleasant surprises in flight. Remember, ETOPS also stands for 'Engines Turn Or People Swim"
Buzz Fuselsasage, Line Mechanic by night, DC-3 Crew Chief by choice.