This album contains images showing the differences between both Phase I and Phase II Dynamic Brake Housings.
The Phase I Dynamic is more rounded, similar to earlier GP50 designs. Noth the additional length of the right side.
The Phase II version is symetrical. Note the differences in the forward right side access door. Early versions have EMD door latches, while later production the door is bolted.
All photos by David Hussey All images are copyright by the author, and may not be used without permission. However feel free to pass along the link.
Dave Hussey