I'm talking about the trans cases with no VIN derivative on them. Are one of those blanks viewed as better than a transmission with a non-numbers matching derivative on it?

 

Take the blank, put a repro tag on it, and stamp the VIN derivative on the case. If you uncomfortable that someone down the road will misrepresent it then make sure you generously post your VIN on-line for all to find this out in the future.

 

They are both equally non-original.

 

In my instance, yes you are correct. And I plan on fully disclosing it if I went this route and actually ever sold the car.

However, in the case of someone actually having something like this replaced under warranty, have you ever seen one of those with dealer documentation? That would be a rare sight I would think. For those cars, they are just non-numbers matching without a dealer invoice then?

 

It isn't "numbers matching" in either case. People seem to think that "dealer installed" is somehow special. It isn't. What difference is it if the dealer installed a different motor or trans or if you did it in your own garage? The whole point of a "numbers matching" car is that the parts (block, trans case) are the same ones that the car was born with. Once those parts are changed (regardless of who did the work), the car is no longer "numbers matching".

 

Well I guess that's true. Never thought of it as "born with", but now I do see your point. Starting to realize why I'm seeing some cars listed as "period correct." That's just a fancy way of saying, "does not match exactly as it left the factory."

 

Right up there with using "tribute" instead of "phony"...

 

non-VIN service replacement parts kind of have a "cool" factor to them, but if they are both used parts, there's isn't really a significant value difference between them and any other VIN stamped used part. A brand new service replacement part with no VIN will certainly have some value...

In this case, a non-stamped service trans is kinda cool, but I don't think it really does anything to the car. Once the born with parts are gone, it's just another replacement.

 

The GM warranty replacement process specifically spelled out that in case of an engine or trans warranty job, the car's VIN was to be stamped into the service part in the location the factory would have put it. That ain't saying the line mechanics always did that...


In this case I would be more comfortable with a non-stamped component than I would with a component with a different VIN stamp. Documentation is the key.

 

When I replaced a rotted frame, I x'd out the original VIN derivative so it was still legible and stamped this car's proper figures in place. Hiding nothing, and if it is stolen or whatnot, the VIN derivative serves the original purpose- to ID the car that it came from. I would think a similar practice would be best for a trans or engine. X out the original, lightly, and stamp in the new correct info. When the above car got a better engine, the block's original stamp was removed and the car's proper VIN stamp was put in place. At the same crazy angle. With totally different stamps, one at a time, 'cause who has super thin close together stamps and a gang stamp holder to do all at once? No one I know.