My first thought is 500 hp is probably going to tear up the AWD system. Secondly, the 6.4 has an active intake manifold runner valve which the LX/LC/LD 5.7 does not have. So wiring and an MDS window switch would be needed to activate it. That's probably just the tip of the iceberg.
I'd be willing to bet a Magnuson supercharger kit would end up being a cheaper and easier route assuming your current 5.7 is healthy.

 

My first thought is 500 hp is probably going to tear up the AWD system. Secondly, the 6.4 has an active intake manifold runner valve which the LX/LC/LD 5.7 does not have. So wiring and an MDS window switch would be needed to activate it. That's probably just the tip of the iceberg.
I'd be willing to bet a Magnuson supercharger kit would end up being a cheaper and easier route assuming your current 5.7 is healthy.

Thanks for the response, I agree with getting the supercharger, it would probably be the easiest and probably cheaper but I was trying to keep it NA and especially for long-term. But in terms of displacement it would probably be cheaper to swap a used 392 rather than taking apart and boring the 5.7 in my opinion? I'm not confident on that though but I don't have the space or proper tools to be able to do that kind of engine work at the moment either.