The problem is the parts
Most manufacturers are phasing out old obsolete wheels seals and shafts.
They are tooling up for the newer designs.
When you start factoring in labor these rebuilt units aren't that much cheaper than a new journal bearing unit
There is no way they will not move their inventory in favor of someone requesting a better exhaust wheel.
This is the business decision that is made way higher up.
Trust me the designers know where the limitations are.
Other companies have redesigned their compressors and turbine wheels to set...
When say 1 of a kind
Can you be more specific?
I've seen plenty of 16oohp cars that are run on the street in all different kinds of platforms.
So what makes 1 of a kind?