Classic/Antique Car Repair: 1949 Cadillac Engine Oil, cam shaft, v8 engine

Question
I have a 1949 Cadillac Sedan De Ville (62 Series) that has a 331 V8 engine.  I would like to know what would be the best type / grade engine oil to run in this car, taking into consideration that I live in an area where temp's can and do range from 25F in the winter to 115F in the Summer.
Thanks in advance for your help.

Mark

Mark

Answer
The question that I have is how fresh is the engine? Does it have a lot of miles on it or is it a fresh rebuild? I would certainly run the run one of todays to brand oils with at least an SM API rating. If the engine is fresh I would use a 10W-30 viscosity year round. If the engine is old and has significant miles on it I would run a 10W in the winter and a 30 in the summer but still with an API rating of SM. There has been some talk of the newer oils not containing enough phosphorous anti scuff compounds to prevent cam shaft wear. The anti scuff compounds have been eliminated from the oils to prevent catalytic converter failure. But I have not seen any testing proof that this is the case or just an attempt by an additive maker to sell more snake oil.If that concerns you then use an API SJ oil as it was for cars prior to 2001.