to answer the legal question in CA, no it is not legal. period. no smog ref will ever pass it no matter how clean someone can make the engine burn. its not a legal engine. meaning, you want that engine, you better have it smogged at a test only center that you got hook ups with and never report the engine modification to any records, especially DMV obviously.

this is completely different from swapping in a whole engine in its entirety into the car, which is only legal if its of the same year or newer and has all the appropriate smog emission control devices.

bang for the buck, nitrous owns. hands down. that guy on HT had great resources to do what he got done.