I believe it is a pretty standard bolt pattern, as when you read the labels on the many different intake cone adapters in the parts stores, it might say something along the lines of "this unit will work on 95-2006 Toyotas, 93-97 Nissan, 89-94 Mazada, 99-2005 Honda" or something like that.

I think its just a matter of selecting the correct one that lists your application. If anything take a piece of cardboard and trace out the bolt pattern. Take that along with some measurements made right a ruler and you should be able to find the one that fits the 3RZ

My adapter is actually from a Nissan 300ZX that happened to fit. But Bevin's adapter specifically said something like "95-2005 Toyota, ......etc" and it worked just fine.