I've always thought this was the product. I've first heard about this as a throttle blade sealer on early Pontiac tri-powers.
DAG#213 here:
http://coatingsystems.thomasnet.com/...g-213?&seo=110
here's a pdf from the original supplier I believe:
http://www.laddresearch.com/SpecSheets/LaddDAG213.pdf
Here's maybe some "similar" products that might accomplish the function:
http://coatingsystems.thomasnet.com/...n-2?&forward=1