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

Jim Lusk said
What I have read is that guys who worked Chrysler's dyno rooms claimed not one 340 came in under 320hp. NHRA factored them to 310hp. Guys on the street said they ran like 350hp 327s. I have also seen tests where pretty much everything else Chrysler sold, with the exception of the 426 hemi, was pretty close to advertised.

Now, consider marketing and other cars/engines in fleet along with racing class and insurance rates. Who would have bought a 383 Dart if the 340 was advertised with more horsepower? Who would have bought a 383 RR/Super Bee for the same reason?

We must have read the same thing. That's exactly what I remember reading. One thing's for sure. They put out more than 275 considering all of the supposedly more powerful victims they outran.