The AC-8s were the first to receive the larger redesigned cab windows as standard equipment that were retrofitted onto earlier AC class locomotives. The locomotives were only slightly larger than their AC-7 predecessors.
Diebert, Timothy S. and Strapac, Joseph A. (1987). Southern Pacific Company Steam Locomotive Conpendium. Shade Tree Books. ISBN0-930742-12-5.{{cite book}}: CS1 maint: multiple names: authors list (link)