Wow, are you sure that isn't a misprint? Most always it was SAE30 in the day?
Not a misprint. Here's the page from the 48-51 Truck Service Manual. LINK
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
