The rocker choice is a matter of opinion as I see it. The shaft style is mopar but when purchasing rockers raises the prices. I went magnum for the reason of having more options with rockers and paying less as well. But neither is going to effect Hp or anything like that. The styles are picked by comfortability and personal opinion. I had no issue setting up my magnum, but Mad Dart didn't like his. Choose whichever you feel. :burnout: