BTW- thanks for the link on the lead additive. It sure seems to be important, as I recall all the hoopla of "Regular or Unleaded" 30 years ago. I realize the problem with lead is the catalytic converter, but I wonder what the difference in a 1965 valve from a 2008 valve that the old valve "requires lead"? Is there a difference in the valves, or just an octane boost? The link you forwarded also seems to suggest (naturally) that it is really important to run real lead. My 1966 FE was, of course, rebuilt in 1997. So, do I have "lead neccessary valves", or "unlead tolerant modern valves"?
