"Rich" wrote in
oups.com:

Of for the days of tetraethyl lead.


Actually lead was an octane booster that helped cool the valves
and guides, and engines that were not built properly for low
octane fuel had iron valve guides which burned out when gasahol
and unleaded fuels were used (mostly chevrolets).

After replaceing the guides (heads) and adjusting the timing
properly, they were fine.

At any rate, lead was an octane (polution) issue, not an alcohol
(gas crunch)issue.