The Nissan 240sx throttle body is 60mm vs. the 54mm of the stock 300zx throttle body. The Nissan stanza throttle body will also work and is the same size as the 240sx. Both are a direct bolt in installation.
how to intall:The diameter of the intake collector (upper 1/2 of the manifold) is slightly smaller than the mating surface on the 240sx/stanza throttle body. To get the full benifit of the larger throttle body, you should port the manifold to match.
If doing this while still on the car make sure to plug the intake with a rag or something to prevent metal shavings from falling into the engine.
The easiest way I have found is to finger tighten the throttle body onto the manifold and draw a circle matching the outlet of the throttle body onto the manifold. Remove the throttle body and then grind at the manifold until the mating surfaces of the throttle body and manifold match. I also grinded 2-3 inches into the manifold so that the transition is nice and smooth.
