1965 fuel requirements

[L J Ferguson]

I have just bought a 1965 Tbird and would like to know what has proven to be the most satisfactory answer to ; 1--100 octane fuel requirement when it's not available. 2--Lead requirement when it's all unleaded now. Would appreciate what has been found to work well and protect the 390 engine.

[lazy390]

hi ya
The Z codes 10.5 to one compression dictates premium fuel anyway and todays fuel isnt the same as when they were made. my 64 pings on anything other than 100 octane.I have changed the jets and had the dizzy recurved to make it tolerate 98 pump gas, but under load it will still ping. If i run 98 and the octane booster it goes hard and no noises but they are dear enough to run without having to resort to that, so i only add the booster when i know im going into the hills or its hot and im going to have the ac on all day.
hope this helps

[arthur44]

Just bought a '64 with a 390 and find that it runs OK on 93. No pinging or other noise...but it needs a tune up and we'll see how it goes after that.