Race cars pick up a lot of non-factory original parts over the years.
The largest engine available in a '65 Belvedere II 2-door hardtop would've been a 426 cu.in. "STREET WEDGE". The aluminum front end was part of the "RACE HEMI" Super-Stock packages: Dodge HEMI-CHARGER (W01) & Plymouth SUPER COMMANDO 426 (R01).