All 767's on transatlantic routes have E+.

It's a bit more complex for 777's. According to the UA website, 23 out of 55 international 777's have been reconfigured. The reconfigured planes are used on East Coast-Europe routes only, as they do not have the range to serve SFO/LAX nonstop. UA has said it will be reconfiguring the remaining 777's starting this fall, and finishing late 2003.

Unfortunately I can't find the relevant page on the UA website anymore!