The 428 in that Firebird...if indeed a Royal Pontiac, Myrtle Motors will not have a VIN stamp or a engine unit number of the same font or appearance as stock.
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.