I don't have a "data", just hands on experience. Literally, it was "hands on" after drag racing another SHO buggy. After a few races, we were sitting on the sidelines, watching everybody else burn up 110 octane gas. After about 10-15 minutes, we were ready hit the road back to camp, and remarked how dusty my polished intake was and went to wipe the dust off and lordy was it warm. My buddy said his wasn't because of his gaskets. His was only slightly warm near the mounting bolts, mine you could hardly touch.
After we got back to camp, my intake had cooled down to ambient but as soon as I shut it off it started to draw the heat out of the heads again. I was impressed to say the least and the rest is history.
Tom