I think they were sold over the counter for a number of years. Maybe someone with more knowledge can help out...as the stuff I am finding is on the internet and easily accessible!
Here's one site:
http://www.guinns-engineering.com/We...%20Casting.htm
according to heartbeat city...the 1969 ZL-1 should have an intake p/n of 3933198...
Where's Charley...or Stefano?
