Why does the 20R head breathe better? Can you say 'Hemi'?
Straighter ports and a plug in the center of the head. I was under the impression 22R valves fit a 20R head. Would really perform with EFI.... The larger valves will drop the cc's a little bit, but you'll still have a higher CR than with a 22R head.
a 20R does not have the plug in the center of the head; its in the same location as a 22R.
