If you go o your Maintenance Logbook 2003 Diesel Truck Schedule B, you will see the 3,750 Miles has "Change engine oil and engine oil filter. ", this is followed by a cross. If you look at the bottom of the page you will see a diamond for Tier 1(rest of the country) and a cross for the California models. the diamond will show up on the next page 7,500 miles where both cross and diamond are shown for "Change engine oil and engine oil filter". It would have been a whole lot simpler if they just printed a separate book for California.
Dean