When I first got my truck I did not have a hand book for it so I used 20w/50w oil to do an oil change. Since then I have obtained a hand book which indicates the use of 10w o 30w oils depending on the ambient temperature. I have looked up on the net but all the oils seem to be for post 1990 cars.

So to my questions. Is any 10/30 oil OK or is one of the synthetic ones the better wayto go, is the modern engine stuff OK for the older Y block?

Regrds Peter

Hang loose and enjoy the ride.

Brisbane Australia