1966 Early 427 Engine Stamp Question

[Steven S.]

Hi. Looking to buy a 66 427/390hp, low mileage Corvette. The engine stamp for the VIN has an S in it after the number 6. I found another engine pad stamp photo of a 66 390hp in Australia, built on the same day, September 9th, 1965, and the stamps are identical.

Does anyone know if this was an anomaly on the early 66 427 blocks?

I have attached photos, and the block stamping looks original to my eye, but the letter S puzzles me. I haven't seen this on any other 66 427 that I have seen photos of built after this.

Please let me know your thoughts.

Thanks,

Steve

[Steven S.]

Re: 1966 Early 427 Engine Stamp Question

Just arrived home, and found the answer in the 1966 NCRS Judging Manual for 1966 Corvettes, 5th Edition, page 90.

" The letter "S" is found in VIN derivatives as applied on engine pads for the first several hundred cars. Example: 6S100XXX "

My guess now is that both cars #269 and #318 are legitimately stamped correctly on September 2nd, 1965, a Thursday.

Thanks again,

Steve

[Wayne L.]

Re: 1966 Early 427 Engine Stamp Question

The very early 66 blocks all have the "S" in the second position of the VIN derivative stamping. I do not know when they stopped using the "S".......

[Michael W.]

Re: 1966 Early 427 Engine Stamp Question

My guess now is that both cars #269 and #318 are legitimately stamped correctly on September 2nd, 1965, a Thursday.

The engine assembly date was stamped at the engine factory. The VIN derivative was stamp later at the car assembly plant. Both engines having an S in the VIN is related to the car's assembly date and not that of the engine.

Obviously all engines must have an assembly date earlier or equal to that of the car.