Richard Doig, who is "Running Rich" on this site would definately be able to tell you. There are some pictures on his site:
http://gtfour.supras.org.nz/ They're under Turbos.
I don't think there are any internal differences though, after all the WRC has the same power output as a standard car. I'd also be suprised if therw were any differences as the standard ST205 manifold is very good- Fensport in the UK say they have seen Japanese cars still using it at over 600bhp.
You might also want to read "Redmist's" project diary- called something like fat cat ST205- he had a play with the WRC manifold and ended up getting it operational by smashing a certain part with the hammer.