The Hemi numbers are totally out to lunch. As delivered, their 425 rating was not far off. However, 500 was there for the taking with just some good dyno-tuning. With both in stock form, the 440 Six-Pack would edge the Hemi in the 1/4 mile. It's 390 HP rating was much more under-rated than the Hemi's 425 number.
The 427 Ford numbers are a complete joke too, unless they indeed were testing the SOHC. The best FE 427s ever made were indeed hot engines, but as delivered they were nowhere near those numbers, not even the ones in the Thunderbolts.
It is too bad that they didn't test an LS6. They were factory rated at 450 I believe and it's said they actually made 500 right out of the box. Those were the days!