I currently have a 89 t2 rx7 roller and an r33 front clip with a rb25det and trans. does anyone know if this swap has been done before and if there is any info or write ups on it that would help. also a list of modifications needed for it to work. thanks in advance.

wont that throw the 50/50 balance way off?

I've never heard of it being done though. I imagine it'd fit with maybe some modification to the hood or firewall, and the transmisson u just need a custom driveshaft.