What kind of gas for 71 350?

Does the 71 350 Buick motor take regular unleaded or do I need to use a lead additive I've gotten many different opinions to date and have been using a lead additve to be safe but don't want to damage anything if it's not necessary.

 

I use just normal 87 octane on a bone stock 200k plus 71 350.

 

91 unleaded recommended in the Owner's manual.

 

All '71 Buicks came with hardened exhaust valves and were designed to run on unleaded.

 

"Good question" I've always wondered about also.

Great, so you would advise High Test?

I wonder how many use High test here?

I use it when I can afford it.

The original engine was just rebuilt!

There was a point where gas here hit $4.99 for regular.
Just before the Hurricane further south.
Now the price has come down to $1.41 for regular or ~ $1.70 high test.

Predictions are w/ the economy @ this time, OPEC gas production will be decreased shortly, and prices will be going back up.

PS:I love the search here on V8-Buick, as I did a search on this question.

Thanks, and Happy Holidays,
Scott

 

Regular! 87 Octane is plenty

 

I have been told that todays reg 87 is plenty as the forumlation of gas back then was much different.

 

I've always used high test premium gas in my '71.

 

Chris,

I try and use the best or higher octane, but really not sure if makes much difference?
I know there was a point where it seemed like I had pre-ignition and it just seemed like it was due to lower octane.
Not sure though....

Thanks,
Scott

 

Is 72 he same? Cuz i saw on the sticker in the engine bay that said to use 91 octane or higher o No:

 

Your owners manual states 91 octane. And '71 and up were designed for unleaded.

DL

 

So these manuals are specifying 91 Octane huh? Doesn't it say 91 RESEARCH Octane rating? :Smarty:

In the US, at the pump the 87, 89, 93, ect. Octane Ratings are the average of the Research and Motor Octane Rating. Ever wondered why the sticker always says (R+M)/2 Method???

So all you guys putting in high test in these low comp, stock engines are wasting your money. These engines, properly tuned, will not detonate on regular gas!

Don't believe me? Read this: http://en.wikipedia.org/wiki/Octane_rating