Your chassis build was 4th week of July and you have second week of July motor. Usually the engines were 4-8 weeks behind chassis builds. Since your car was close to the end of the year, I suspect the chassis caught up to the motors cast.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.