I built an adaptor plate for my LT1 to Z32 5 speed using a 3/4in aluminum plate. I have a small mill but cutting out the center was a PITA. Bought a late model flywheel out of a 95 Firebird I think, bought several months ago. Will use an earlier push type 10.5 in pressure plate which bolts up and pushes the pressure plate out far enough. A 2005 Xterra pressure plate has the correct input shaft size and is bigger than the stock Z32 disc. Have not bought that yet. My motor is in the car with custom mounts, pushed the trans back about 4-5 inches. Sorry for the lack of exact measurements but I have not worked on the project in 2 months due to other obligations.
The stock Z32 trans may not take a beating but they are cheap around here and I know the turbo trans is good for 600 hp. Spoke to a local Nissan tech that said he has seen the turbo trans handle more than that.
Have the accessories mounted for fitment only, they will get some love before install. They are out of a 95 Capric and will work without mod. Only real custom work is the mounts, oil pan, and had to modify the drivers side header but passenger side fit perfect.