440 hp 2

-- Actually the mymopar link shows variations for several different years. The six packs were the 390 HP. You cant just look at one year though.
There is a ton of information in both those links.
Here are some engine specs that may help. General, tune up, and valve.. --
---- You've hit it - good research job. -- This answers the question re HP & 6 Pack vs. Std. --

Various 440s.JPG