I have always wanted the ability to adjust a car’s displacement instead of relying on engine transplants. With such a thing I could more easily change a Hemi Challenger into a Trans Am Challenger replica.
There would have to be weight reduction as well. A small block LA engine is not the same weight as a Hemi.
They have ballast
In reality, ballast is adding weight, not subtracting it. Our current “weight reduction” is just a general drop in weight, not where the weight comes off.