You may bring this Land Cruiser to California but it will need tio undergo a Smog Check Referee inspection (in California). The smog referee will need to ensure the engine swap from Toyota to Chevy was done properly and the new engine does not pollute.
It is important that while the Chevy engine was installed in this Toyota Land Cruiser, the Chevy engine's emission components were installed with the engine was well, including the catalytic converter and PCM. The smog referee will check every detail to make sure the Chevy engine is installed exactly as it would have been if it was still in a Chevy vehicle.
After the referee's inspection, if the Land Cruiser passes, the referee will affix a Blue Tag on the vehicle's chassis indicating it is California emissions legal. Subsequent smog inspection can be obtained at privately owned smog test centers.