Observations....
Sidelining early suggestions of 427/600hp and 482/800, the highest estimate so far is 585hp and engine size guess is 289ci. That's 125hp per liter.
Back in 1988, the last Cosworth DFZs in F1 were 3.5 liter, producing 590hp for 168hp per liter (but needed a rebuild after 200 miles)
The Ferrari F355 was the first stock street engine (I think) to produce over 100hp per liter (3.5liter, 5 valve, 375hp, 8500rpm top end, 107hp per liter)
When are you going to close the book and give us the details Brent?
Cheers,
Glen