360 Under Rated?

I just read a article on the 340's being under rated and I was wondering if the 360's of the '70's were under rated as well. I don't know how accurate the article is but it claimed that the '71 360 had a gross horsepower of 275. Advertised horsepower was at 245 - 255, I guess it depends who's information that you have read. What you guys think about it?
Author: admin