Just for reference here's the page from the 59 Owners manual with oil chart:

http://chevy.oldcarmanualproject.com/chevyowner/59tom076.htm

Most people now a days think that using 5 and 10 weight multi-grades is some new efficiency thing.... seems that they knew that in the 50's.

Like I said, 20 or 30 weight.

Last edited by pfarber; 12/22/2013 10:22 PM.