383 4bbl '71 Cuda would be the same as the '71 Challenger posted earlier. Looks like the only 4bbl 383 available in '71 was a 300hp detuned, 8.5:1 motor, probably with the 2bbl cam.
Never noticed it before, but looks like the '71 dealer info shows both rating systems, and says 250 hp and 325 ft/# for the '71 383. Compared to 245/320 for the '74 360.