jbrad13 - Full synthetic or a blend will work well in your V10. Your engine came with a blend so staying with a blend or going full synthetic will be OK.
The original V10 Ford used 5W30 then switched to 5W20 as part of the 3 valve head engine with the 2006 model year. Per Ford's literature - "New GF-4 engine oil replaces GF-3. Benefits include enhanced fuel economy, lower phosphorus reducing catalyst poisoning and decreased engine piston deposits and sludge (GEN-ES-10032)". The GF-4 was the ILSAC (International Lubricant Standardization and Approval Committee)API standard back in 2006. The current Motorcraft 5W20 blend is formulated to meet a GF-5 standard.
Mobile 1 full synthetic 5W20 has been serving me well enough per my analysis reports I have done with each oil change. Mobile 1 meets the GF-5 standards.
For more information
http://www.oilspecifications.org/