If in Club

I would take a window seat on a narrowbody. The window seats on the 767 do not have a blocked seat next to them.

If you want direct aisle access, either take the narrowbody or EF pair on 767.

Don't take the window-aisle pair on a 767 under any circumstances.

If in Traveller

I would take 767 due to 2-3-2 configuration. Each row has two window seats, four aisle seats and only one centre seat. 85.7% of seats are either window or aisles.

Narrowbody on the other hand has only 66.7% of seats as either window or aisles, leading to a more crowded feel. Window passengers have to climb over two others to reach the aisle, against one on narrowbody.