Tom -
On Ford 289 HiPo engines, the serial number of the car the engine was originally installed in is stamped in the block on the right hand (passenger) side just above the rail of the
oil pan. Here is an example from a Shelby GT350:
This generally applies ONLY to the 289 "HiPo" engine - Ford did not usually stamp the VIN's of non-HiPo 289's in the early sixties. The serial number decoding, by example, is "6R09K" (where 6= 1966 Model Year; R= San Jose Assy Plant; 09= Mustang Fastback Bodystyle; K= 289/271HP High Performance engine), followed by a six digit vehicle sequence build number.
I sincerely doubt that 289 Cobras have any such VIN number stamped into the block. The reason I say that is, the engines in Cobras were installed at SAI, not at a Ford or AC facility. As far as Ford was concerned, these engines were "aftermarket" sales to an outside vendor. They would have been just like Service replacement parts - date coded for whenever they were manufactured, but without a vehicle VIN number.
I certainly wish Bob well on his research (he has written an
exceptionally comprehensive book on the small block Ford 289/302 engines), but I don't think that this one will help him out much.
I would venture to guess that there are very few original Cobras around that still have their original engine intact.
regards,
cobrajeff