have a 1965 Buick Skylark - what is the best gas to use 87, 89, or 91 all are full gas no ethonal. Do I need to add a lead additive and if so how often? Cheers -
Are you in New Zealand? (I see "kiwi" in your name) The RON numbers of NZ petrol are different from the fuel in North America.
if its a two barrel the 91 should be fine for a 4barrel wild cat you will need 93 most likely mine requires it/