Well, I guess it all depends on IF the Heritage Certificate for a particular vehicle lists teh serial number of teh engine, transmission, diff, along with body number. That is super-matching, and probably harder to find than not as I suspect many B's out there have had companion parts cars provide major component transplants over the years. Even minor transplants - as I recall swapping axle shafts from my '64 into my '67, and although eng/trans are proper to the '67 I cannot attest to them originally been there. But, if anyone is interested in an originally BRG '67 with backup lights, and/or a '64 (currently medium green, may have been always such) I can hook you up as I need garage space to disassemble my originally light blue, currentl red and gray primer, '56 A.