Do you use premium unleaded in your 350?

[Stocker]

Originally Posted by Critter

That sounds like you might need to adjust your timing a bit.

I would agree, but for one fact: the only time it ever pings is when the engine is operating under exceptionally heavy strain, which isn't often. The other 99% of the time it operates perfectly. Maybe I'm wrong, but given the circumstances, the timing stays.

[GASoline71]

Also rmember... if you're runnin' the stock unmolested engine from 1969... the exhaust valve seats in the heads will not be hardend from the factory, and you'll need to run a lead additive in it every few tanks.

Gary

[special-K]

I run Cam 2 in my tow truck because it doesn't get run much and I went 'round the ethanol merry-go-round already. After a rebuilt quadrajet and a flushed out tank I just put 5 gal. at a time in.

[oklalawnboy]

Originally Posted by 68gmsee

Octane determines the rate of combustion. The higher the rating the slower the combustion. Unless your engine is specifically designed for higher octane there really is no need to use it. Colder weather will cause the harder to start issues but you could play with the timing a bit to see if it helps, otherwise, I'd go back to what you know the engine likes.

Don't forget that a lot of companies change their blending of fuel depending on the time of year so you may also be experiencing that. You may also be able to adjust the timing and idle air mixture to compensate .

X2 on the higher octane being harder to ignite. If your not running high compression you don't need premium.