ever consider the SR20 det for some race classes in Japan they take out the 6cyl and fit the sr20 ran get the same power with a lot less weight can be found with 6 speed gear box
I know of a 260z 2seat in toowoomba Qld. that is being fitted with the nissan V8 and twin turbos. But have not heard of the toyota V8 in any. As far as engine bay size I had an XE falcon with a 351, and have a 260Z 2+2. The datsun engine bay is 25mm widder than the falcon measured between suspension towers and the same from radiator to fire wall. There is also a celica in W.A. with a 1UZ so they cant be too big for a zed