No major league baseballs are 5 ounces just like regular baseballs.
Major League Baseballs are made in Turrialba, Costa Rica; this is most certainly true!
Rawlings make Official Major League Baseballs
The National League Spalding baseballs along with the American League Reach Baseballs (owned by Spalding) were used in Major league baseball for about 100 years until Rawlings took over in 1977, and Rawlings have been making major league baseballs ever since.
Roughly 7 dozen, or 84 baseballs.