I have an original 1961 Chevy C10 with the original 235. It has 81,000 actual miles. I've put the last 10,000 on it in the 40 years I have owned it. The engine has never been rebuilt. Since I have owned it I have always used a straight 30W Petroleum based engine oil (I live in Texas, so it gets hot). Changing oil and wondered what the current thoughts are for the best engine oil considering age and mileage. There are so many choices and synthetics and blends now. PS, it does not smoke or leak and would like to keep it that way. Thanks for your input. PSS My truck is in the Gallery.
