Production means being made by the many ether for race teams or for cars for the people.
The factory (all car manufacturers) have made experimental engines and some were racing engines. The Chrysler example was the ball stud HEMI in which only a few were made and 1 or 2 survive.
Another Chrysler example is the Turbine car. A few were made and fewer survive. The jet engine (for lack of better terms) that powered the car was made and installed and worked. (Very well from what I have read) but never sold to the public at dealers.
They created and made the engine and/or car but never produced it for consumption for the public. Don’t confuse that with production. Production is mass produced for purchase.
