Gust saying Hi and looking into putting a V8 in my 1990 RHD Eunos Roadster/MX5 from Japan. Has anyone put a V8 RHD MX5?

 

Interesting build.
I do seem to remember that Flyin Miata does have the parts and instructions to take care of right hand drive cars.
Your best bet would be to call them, presuming you are figuring on a LS & T56 build.