becasue a crate 472 is junk compared to a home built hemi... the Eddy heads that mopar uses and licensed are crap... stage V is the best head due to the R&D they have done (and did i mention there about the same price lol... and we run race hemi's on the street, pull some cam and duration out of it and they are very happy...
and the mopar performance book also tells you to run like 80-85 range jetting (different in every corner) and they really need to be about 72-75 (different in every corner)