your maxima engine, and the VG30DETT engines are a shitload different. even though it is the same engine code, the DETT has a different bottom end, although same stroke and bore, are built FOR turbo's, two of them nonetheless. also oil cooling, and lines and all that. do not think they are the same engine at all, you cannot put a maxima engine in a 300ZX, and vice versa. but this is the later generation i'm talking about from 1990 and on, but i really doubt the manifold from an older one would be compatible as well. It's not a honda, you can't really bolt anything together like that. same with the lexus IS300 2JZ block and the supra turbo block, they are a lot different.
it will be a lot of modification to get the piping and all that stuff, personally i don't think it's worth it to turbo one. if you are looking for power, 75 shot of nitrous MAX! it's a family sedan.