The good thing about this is if you do this and you drill the block vs the heads, the cost now might be a little higher, but you could down the road swap heads much easier. That would leave you open should you be super lucky and find a set of Hammer heads or even "just" AMG heads. That'd be one hell of a deviation from your original 4.5 (as if what you're doing now isn't already).

Edit: Come to think of it... have you checked if M119 heads would work? I know the M119 is different BUT at the same time it's the "Natural evolution" of the 117 and the heads just might work... Imagine E500 heads and cams on the 5.6 you're doing.

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2021 Charger Scat Pack Widebody "Sinabee"
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1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k