Long time since I've been on this website because of my other car. But browsing 300zx websites I have figured out Jim Wolf Technologies now makes a swap kit for use of a 350z 6 speed on a 300zx.
How this kit works is it uses a 300zx z32 automatic bell housing and a custom adapter to mate the 300zx automatic bellhousing to the 350z 6speed manual gearbox. Crazy.
But what I have reasoned out is. The bolt pattern on the 300zx manual and automatic bellhousing is the same. If I used one of 240hokes l28et to z32 transmission adapters, had a 300zx AUTOMATIC bell housing machined back, then use JWT 6 speed gearbox adapter, then the only missing piece would be a custom driveshaft and transmission mounts.
I do not have the money or the time to do this project but I figured I would post up this idea and hopefully someone will try it out!
-Nick