The r33 gtr as I know of now has to be 25 years old to be imported to the USA. The r32 is already legal and is an example of this rule in effect. I looked up this NHTSA sheet and it says here that the r33 is legal to import, and they even assigned it an eligibility number! Did I read it wrong, am I right, or is there some catch I’m missing?
I found a Facebook post from an import tuner that helps to explain the situation. Basically, you can import one, but it must meet certain requirements that can be difficult to acheive.
When VCP17 was revoked and VCP32 was put in place of it that suddenly changed the requirements and eligibility of all R33 Skylines to later being specifically the 1996 to 1998 R33 GTS and GTR with dual-side air bags. This also further complicated the process because traditionally MotoRex Inc was faking the funk back in the day by avoiding OBDII through mis-declaring 1996 and newer Skylines as 1995 so they didn't have to do OBDII on them (taking the easy way out). Today there is no faking the funk under VCP32 and any R33 that is imported under VCP32 must be brought into conformance with the FMVSS and also EPA which means OBDII is required. While this may not sound like a complicated process it actually is and also very costly.
I'm not an expert at importing JDM cars, but I believe what the post is getting at is that there was a VCP17 that was allowing their import, but that was nullified and replaced by VCP32, but thats only for models with side airbags and you must install a working OBDII diagnostics. That sounds impossible to me, but the post at least makes it sound possible if not extremely difficult.