I've never seen one. Few people in the U.S. Offer a drive in drive out conversion, but nothing you can order (well last time I checked). Mazworx did the best gearbox adaptor plates, but require bell housing machining. The wiring isn't too hard. Bonnet clearance is a big issue without modding the crossmember. From someone who did the vh conversion, don't bother. Lsx, 20b or vgtt.
A Conversion manual I wrote http://docslide.us/documents/nissan-300zx-vh45de-v8-conversion-process-28-nov-2009.html
Try proformance vh they are in the U.S. And the guy has a biuld thread on the forum, good luck with it, hope to start my biuld soon.
Chuck this in too. http://collinsadapters.com/index.ph...k56de-to-350z-transmission-adapter-plate.html