Yep it is, but where does the Giken head fit into the overall picture ?
It wasn't a competition part, it wasn't allowed in the US, yet it put out 15-20% more horsepower than the LY, yet there was no avenue for any vehicle with one fitted to run in that I can find, except for a rally spec 280ZX that ran in the US for a SCCA rally, which poses the question if it was allowed as a rally spec, why not for circuit ?