im not claiming anything here, but i always thought from reading on here that with a 2.02 int valve on a J head up against an x head, that full ported the J has more potential???
well #'s mean nothing. except to the guy pocketing the $$$,
and some people here who think HP & flow #'s are gospel.
At the track however, you'll see what the X head can do thats been ported by somebody who knows WHAT TO LOOK FOR IN X-HEADS.
cheers.
