I Might Have Found Something Pretty Cool.....

E49( I think) Charger? Australia version? No actual idea, total guess from left field. But the Australian RT Chargers had some nice power for Hemi Slants.
The 6 cylinder in the Valiant Chargers (Australia) that you are thinking of were not Slants unfortunately. Do a youtube search on TuffR6 and Mirabito performance to get acquanted with the Australian mopar 6. They did have the Slant 6 in Australia also but with nowhere near the power of the 265 Cubic inch "Hemi".