I would like to learn about what kinds of locomotives Conrail used for small local freight moves and what the opinions were on them. SW1500, GP9, GP15, GP38, U23B, etc. 1970s-1980s time frame. What's a good resource?
The April 2016 issue of Railroad Model Craftsman had a nice overview-type article about the history of Conrail. It may contain some useful tidbits.
The April issue of Railfan and Railroad, published by the same company also had an extensive spread on Conrail.
Start here: http://conrailphotos.thecrhs.org/ConrailEquipment/Locomotives Below each photo is a link to a page for different manufacturer's locos. The separate pages for each manufacturer then contain links to pages for a specific loco model.