Should I buy this 440?

Unless Chrysler was playing games with the numbers back in the late ‘60’s early ‘70’s the low performance 383 made 330hp and the high performance 383 made 335 which amounted to 5 extra horsepower. The low performance 440 made 350hp and the high performance 440 made 375 which amounted to 25 extra horsepower. So where did Chrysler come up with an extra 65 horsepower in 78?
Gross factory power numbers are pretty useless. Net at least has a standard behind it and even those can be manipulated to some degree.