Looking at the yearly power and torque ratings of stock 360-2 engines (E57) I was surprised to see that they peaked in 1974-1975:
year power torque
1971 175@4000 285@2400
1972 175@4000 285@2400
1973 170@4000 285@2400
1974 180@4000 290@2400
1975 180@4000 290@2400
1976 170@4000...