74 440 power uppers....

You cant mill the heads that much. Just put a mild cam in with a good valve job and intake/carb.

My 77 smog 440 in my 70 Coronet with a Mopar 284 484 cam, dual plane, 800 Holley, headers and 3.91 ran 13.80 with a bog in the carb and bad tires. Some tuning and sticky tires could have gotten mid to low 13's easy.