1968 Plymouth Valiant First Gen HEMI

Likely reason for passenger side shock tower fabrication is to keep the engine located to the passenger side for master cylinder and steering box / shaft clearance. I'm sure you caught the offset master cylinder adapter also.

To keep the Hemi from being high in the engine compartment, the Stage I Hemi I installed ended up pretty much dead center vs the normal OEM 1-3/8" off set to the passenger side