Plymouth Duster of 73
IMHO, Sounds too "big brother" to me. The government and the unsurance companies really have no business getting under the hood of your car. My 67 barracuda was a 225 /6. Will be 408 small block V8.
But i guess you have to deal with the motor laws you have in your country. Hopefully the US DOT and EPA dont get wind of this and try it here.