The engine was not a '48 and was not stock. :-) Rick Sent from my keyboard On Oct 10, 2011, at 2:46 PM, <corvallis at peoplepc.com> wrote: > From http://forums.aaca.org/f169/gas-1948-buick-310940.html > > "Any 1948 vehicle was made to run on low lead or no lead, 70 octane fuel. > That is all they had back then. ..."