If it helps, from a John E. Bush article on Trains.com:
"In another of the series “25 things you may not have known about Big Boy locomotives,” the turbo-generators were located in a totally differently location than on previous UP locomotives. Interestingly, it was decided to mount the generators low on the right side of the locomotive in the space between the last driving wheel and the front of the trailing truck frame."
Couldn't prove it by me...
"At any rate, on the latest Lionel model of 4014, the dynamo is located down low, on the Engineer's side, at the bottom of the firebox. Obviously this is incorrect for how 4014 appears today, but the Lionel model depicts the "as delivered" version of a 4000 class locomotive. The UP quickly relocated the dynamos to the top left on the boiler, just forward of the cab."