What are the legalities and smog requirements for either swapping a smog exempt motor into a smoggable car and vice versa(new motor into old car).

 

I think in California you can't have any fun if your vehicle was built after 1975. Basically, you can't modify working emissions equipment, non working emissions stuff can usually be removed, but not always. The two most commonly removed items are catalytic convertors and air pumps. You will need to check with a local DOT office for your state to be sure...

 

well you cant install any motor that doesnt meet that years or newer smog requirments across the nation. so for instance if you have a 90 fullsize truck you would have to put in that year or newer motor with proper smog equipment. you couldnt run carb if its efi etc.... cali is the most strict of course .