Mopar event at Sacramento Raceway Sept 26

GREEN DART 5 said
Does anyone know what the green DeSoto (second car on the trailer) had for an engine. It has that “sleeper” look but very fast.

He was pitted next to me.. I never spoke to him, but those were known to have either a 331ci or 354ci Hemi. first generation, of coarse.
Sounded decent. What did it run?