340 4 barrel and 340 6 barrel: were they really UNDERrated?

Newbomb Turk said
It’s very easy to make over 400 hp with a 340.

It takes ZERO port work, a Strip Dominator, good headers and a cam with 280 degrees of advertised duration.

And you can shift it at 6k.

My cousin use to race late model and the track was dynoing engines for coming up with rules when bring in Chev crate engines, and said they had a hard time making under 400 hp with the Mopar to try and match the Chev crate.