Perhaps use the black key which limits the Hellcat horsepower to 500? I’m not sure how Norway confirms a vehicle has no more than 500hp.
I don’t know if the 6.4 intake manifold will fit the 6.2 heads, but MMX Performance should be able to answer this question. From looking at the MMX conversion kit, going from the 6.4 heads to 6.2 supercharger, an adapter plate is needed.
Hellcat Supercharger Adapter Kit by MMX
www.modernmusclextreme.com
I would guess you would need an adapter to fit the 6.4 intake manifold to the 6.2 heads. Perhaps MMX has an adapter for what you need...the reverse.