 The result is a locomotive that has the frame, body and trucks from an ALCO RS3, but using fan assemblies and EMD 567 prime movers from retired passenger engines, such as the EMD E8, in place of the original ALCO 244 prime movers.The principal visible difference on the Penn Central/Conrail rebuilds is the addition of two conical-shaped EMD switcher style exhaust stacks in place of the one rectangular-shaped ALCO stack and a raised hood.Later rebuilds would just have a raised feature on the long hood to accommodate the larger prime mover.