The BW (Now Tremec) T56 is not do-able in a Nissan Inline 6 motor. Further, the trans requires a special flywheel and clutch assemlby that is a reverse design. Simply put, it will not work. Further, the cost would be well over $2000 just for parts if it would work, not to mention having the proper input shaft machined to fit. I have one in my Z, but it is mated to a Stroker V8 Chevy motor. That is about the only way to get one to work. T5s from the 280ZXT will work with some mods for mounting. But you really don't need either of these unless your Z is making serious (Above 300) Horsepower and Torque. Good Luck
I have a websight bookmarked at school for a company called AEM. They put a T-56 onto a turbocharged L-28 motor. I have heard through the grapevine that it is not too difficult. I will post the sight of the company tomorrow and you can call and ask details.
I'd love to see it. And lets say that you can...Unless you are turboing or have another means of high HP, why would you want to add the extra 40+ pounds just to get and extra gear that is whay over driven for a low torque vehicle?
It cost me $1200 for a used T56, plus having the drive shaft made was another $200. Add to that the time and expense to modify the trans....... I can't wait to get that URL....