Hmmm... As to weights.
EMD tried a 1200 hp passenger locomotive again, and actually managed to sell to the Rock Island!
The "Aerotrain" demonstrators -- famously trialed on the New York Central and the Pennsylvania -- had 8 or 10 car trains, but the cars were 40-foot, aluminum bodied, derivatives of highway bus designs: so the train weight may have been comparable. (Rock Island had a Talgo train -- built by (?) ACF -- pulled by the same sort of locomotive.)
As for the power, EMD's LWT-12 locomotive got its power from a 12 cylinder 567 instead of a 16 cylinder 201A, and transmitted it to the rails through only two traction motors. (Performance seems to have been adequate on more level railroads, but didn't impress the ATSF on a later demonstration stint.) According to a "Popular Mechanics" article linked from the Wikipedia article on the LWT-12, the locomotive (which had an aluminum body: EMD really tried to keep the weight down) only weighed 175,000 pounds.
I suspect, but haven't checked, that the TA was heavier than some of the Zephyr, etc, power cars that shared its 16-201A power plant. In retrospect, I guess it was an "in-between" model: a half-way point between the light-weight streamliner power cars that preceded it and the bigger E-series locomotives that EMD sold as steam replacement for conventional trains.