I'm trying to purchase a BMW e36 3 Series with a 6 cylinder engine but I'm finding most on the market aren't originally 6 cylinders but 4 cylinder cars which have been engine swapped to 6 cylinder engines. With quality of work aside, is this legal? None of the cars I've seen have updated books reflecting the new engines. How hard would it be to get the book updated if I was to buy one of these vehicles. From the research I've done and the people I've spoken to it seems to be a legal grey area. Is this true? I've also heard that changes in displacement of less than 500cc is allowed. Any help on this matter would be appreciated.
