You can swap the complete engine out of your Chevy Suburban if that's what you choose to do. It is not necessary to keep the original engine block. Just make sure you keep the original emission components (aftermarket parts will work as long as they were built for your correct engine size and year). Also make sure you are not mixing and matching emission components. All smog parts must belong to the same engine size and year.
One important thing to remember is that if you are swapping with an identical engine to the original engine you will not need a Referee Smog Check. If you replace with any engine size, design or year model other than that which your Suburban came equipped with, you'll need to have the engine change inspected (smog checked) by a California State Referee.
The Referee will ensure that the job was done properly and that the new engine does not pollute; and passes the smog check. If all is well they will issue you a BAR label which will be placed somewhere on your vehicles chassis which will be an indication that the vehicle is California legal. Subsequent smog checks can be obtained at any smog station. You can contact the referee by calling (800)622-7733.
