Amsoil makes a 10w40 Signature oil that has 1265 ppm of Phosphorus and 1378 ppm of of Zink. Amsoil also has a break in oil with very high levels to provide cam lobe protection. Use that. When you feel the rings have seated, 1500-2000 miles. Then put in the Amsoil 10w40, worked for me in my 1959 235 engine.
