Meaning of "numbrs matching" opinions please

[Keith Tedford]

Too many people play with words to make you assume things that probably are not true. The simple question is: "Is this engine original to the car?" Nothing vague about that. When money is involved, beware.

[LS6 RAT]

Rick,

Your "numbers matching" inquiry is tough to answer easily. My opinion is that there are only 3 items that can be considered numbers matching. This assumes that what we are "matching" is the VIN plate designation to the cylinder case, transmission case and frame/unibody that contains the VIN or a partial derivative of it.
Another argument can be said, about the Protect-0-plate metal card that contains the assembly stampings, and that the engine, transmission and rear axle can all be "matched" to the POP.
Beyond this, I would say all other components could be properly dated for the build of the vehicle, or contain the proper casting numbers associated with the inventory of parts used to build this specific vehicle and its options.