What were the production years for the GP 38?

Model Railroader Prototype information for the modeler
1

I had the info around here somewhere at one point but now I can’t find it. Does anyone know the production years for the GP 38?

Thanks,
Dave

2

The GP38 was built between 1/66 and 8/71. The look alike GP38AC was built between 2/70 and 12/71. Diesel data from Andre’s GM Serial Number Page.