What would it take to make 1.44 lbs-ft per cid ?

Well, the description of the 408 implies low buck…….which doesn’t coincide with tons of head r&d.
(After reading the article the engine appears to have TF heads)

I’m sure plenty of time was spent on the 371 heads for the contest.

RPM heads that flow 270 will easily make 550hp+, using any easy on parts Chevy lobe SFT cam and iron 1.5 rockers.
That’s with zero velocity r&d.