Numbers Matching

January 18, 2011

Ah, the age-old question. Another term like "survivor" or "restored" that conjures certain mental images that, upon further inspection, doesn't seem to me your criteria for the term used. Numbers matching may mean as little as since the car originally had a 396 engine and it still does have a 396 engine (no matter that 1966 Chevelle has a 1969 engine), it's numbers matching. To me, this is a pretty good stretch of the term. A dear friend of mine even considered a 427 engine a matching numbers engine because the engine had a partial VIN stamped on it. Now, this partial VIN was a match to some car somewhere, just not his car but he still considered it a matching numbers engine.

My blog here, so here is my take on the subject. Numbers matching means the primary drive line components, interior, and paint are true and original for that car particular car. Naturally for a car that is 40 plus years old, nobody would expect it to have the original spark plugs, oil filter, air cleaner, and other items that would be replaced under normal maintenance. The engine (1968 and up at least) and transmission were stamped at the final assembly plant with what's called a concealed or partial VIN. Chevelle engines built from 1965 through 1967 are generally limited to the 396 cid and high performance 327 (RPO L79) generally got this partial VIN stamped on them as well. Before 1968, small-block V8s and L6 engines generally did not get stamped with a partial VIN. In 1968 a federal law mandated the stamping for all engines. Transmissions, and most frames, also received a partial VIN stamping.

This partial VIN is directly associated with one car and, for 1965 through 1967, consists of a single digit for the model year, a letter for the final assembly plant, and the sequence number of that car for that plant. For 1968 to 1972, the partial VIN also included the number "1" at the beginning to indicate Chevrolet. Since most 1964 through 1967 small-block V8s did not get a partial VIN stamping, there is no way to tell if the engine is indeed original to the car since there is no real number to match to the car. The engine identification alphanumeric stamp from the engine plant should an acceptable date and suffix code for the car, but with enough searching an acceptable engine block can be found. Correct engine for the car? Certainly. Original engine to the car? No way to prove or disprove.

Now to my major point. Since the drive line is the major feature of a car, the engine and transmission should have the correct partial VIN to be considered numbers matching. Other engine components such as the cylinder heads, intake and exhaust manifolds, carburetor, distributor, etc. do not have a partial VIN stamped on them but should be date and part number correct for the car.

A secondary point, and again in my opinion, the exterior paint color and interior color & seat type should match the current paint color(s) and interior noted on the Fisher Body Number plate, aka trim tag, cowl tag, etc. I know many people do not like certain paint colors or interior colors and often change them. While these changes may be correct for the given year, they don't match the original so, in that arena at least, numbers matching goes out the door.

So, agree or disagree, that's how I see it.