Nice!
There used to be a company named Monster Miata that put 5.0s in them turn-key. I looked them up and I'm not sure it's the same company.
That said, I think it needs more power. twin turbos?
I'd like to know how they managed to get 50/50 weight with a V8 shoved in a car originally designed for an I4. Think it would be way nose-heavy but I guess where there's a will there's a way.