Yep, 5 liters max. Before 1970, you had to actually build a production five liter motor. So there were Boss 302, and Z/28, and AMC 304. Mopar only had 273s they didn't come to play. In 70, factories were allowed to destroke existing engine combos, so now Pontiac, Plymouth, dodge became players, along with AMC's 304. Chevy discontinued the 302, put 350s in the 70 Z28, Ford went to Boss351 in 1971.
