slant 6 oil weight

beebeeri000 said

ok so this might sound stupid, but what weight should i put in a high mileage slant 6? chiltons says 10w 30 / 10w 40 where its regularly above 32, but the guy at costless said for a 70's engine it needs straight 30 oil. so im not sure what to use and i dont want to accidentally damage my engine.

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The Chrysler and Chevrolet Racing manuals said straight 30w oil will result in the least wear. There is no reason to run synthetic oil. Synthetic oil may cause your seals to leak. Old school said, use good oil, change it and the filter every 3,000 miles. You will never have an oil related problem unless you do something stupid. 10w 30 is OK. If you are using excessive oil, try 20-50. I do not like light oil, all the talk about heavy oil is much a do about nothing in my experience. And I have a lot of experience. You are not stupid, it is a overcomplicated subject. Now watch what happens...