SWEPCO GE-??, Alliance, NE, May 14, 1984, photo by Jim Altman, Chuck Zeiler collection

I need help identifying this locomotive. I traded slides for a while, and acquired this one, but don't know the locomotive model.

The slide is labeled: SWEPCO (Southwestern Electric Power Co.) GE "Super 88", Alliance, NE, 051484, one of 8 made - see p.33 in X2200S #68.

I do not have access to that issue of Extra 2200 South. Judging by the buckets on the stacks, the locomotive is obviously out of service. If you have any clues, please leave a comment. Thanks.