I think that swap would be a bit involved. I have a first gen miata with the 1.6L. There is a lot of spare space in the bay with such a small motor. But the new Miata has a 2.0 or 2.5L. The already tight engine space mixed with the varying layout looks like a headache to me. With such a compact
space it seems like you would have to remove a lot to fit anything larger in there.
I'm actually doing the opposite and upgrading the miata to a v8. Good luck with a swap out!