Rule of thumb for converting cc's to ci's is 61 cubic inches per litre. Or for dummies like me, 100 cubic centimeters equals 1 litre equals 61 cubic inches.
Or, 427 cubic inches equals 7 litres.

Now, get out the ole calculator.
2.77 litre V8 = 3.5" bore x 3" stroke, give or take .25".