I bought my '66 C10 about 4 months ago. It has a late model GM 350 crate motor. I would guess that it is no more than 4-5 years old and has less than 10K miles on it.
Does anyone know what weight oil is recommended in these new crate motors? I'm running Castrol GTX 10w-30 right now. I'm would like to run Mobile 1, 5w-30 if that would be OK. I didn't get any motor paper work with the truck, so I don't know what the factory reccomendation is.
Thanks,
Steve
