Engineer James,
Your copy of the Diesel Spotters Guide should have a photo and info about the EMD GP39-2 locomotive.
As mentioned above, the GP39-2 is a turbocharged unit, and rated at 2,300 hp.
The CSX units were originally Reading RR units, built in 1974. They went to the Delaware & Hudson, then were folded into the Guilford System when Guilford took over control of the D&H. Canadian Pacific ended up with the units, didn't want them, and sold them to CSX.
When the units arrived on CSX property, most were still in their former D&H "lightning bolt" color schemes, while others had been repainted in the Guilford gray w/ orange band color scheme. Some of these units kept these colors for around 6 years before they were finally repainted in CSX's "hockeystick" color scheme.
I have had access to current CSX locomotive rosters, and the GP38 units have been off of CSX's active duty locomotive roster for about 4 or 5 years. The last to go off service were a few GP38 units that were assigned to Maintenance of Way service and painted orange (known as "Pumpkins"). Although quite a few units were scrapped, a number of former CSX GP38 units are still active on shortlines. Other units, having been rebuilt and upgraded with dash-2 and dash-3 technology, are currently operating on some major rail systems. One of the orange "pumpkins" is still sitting in Waycross, GA, crudely lettered "BLDX".
There is a good Locomotive Roster booklet that is produced on an annual basis by Jim Kerr. You can obtain a copy at most hobby shops that carry railroad stuff. It's also advertised in Trains magazine. This booklet is hip-pocket sized, and provides you with info. about locomotives on the major railroads and a lot of the shortlines in the U.S., Canada, and Mexico.
ACLfan