The Ps flow a little bit better, unfortunately the spark plus exists straight out. Instead of an angle. So they cause header issues. Their is a simple fix but its very expensive.
you have to have special headers to run these heads and they dont sell them for mav's they have them for the 80's 90's mustangs and are expensive $$$$$ and even then it's still close http://www.google.com/imgres?imgurl...=G&gbv=2&tbs=isch:1&ei=ELSRTL7uHtGwnAfYzYywBw