I want to go racing not inspecting. Let's return to the common sense rules of the 1970s BEFORE all these specialized racing motors came into being. If it looked like a Chevy II on the outside and didn't have a cross flow head you got so many cubic inches and if you finished in the top three you were checked. If it was a different engine type you got a different displacement.
I have Honda F motors that started off as $500 E-bay basket cases and the D2 rules act like they are plutonium. It should be up to the car owners what parts they want to put inside their motors. The cost savings come from using stock castings not stock parts that might fail and cost you a whole motor. In most cases the stock parts are as good or better than the aftermarket parts. The entire numbers matching thing is a joke. If you race for a few years you will end up with a collection of damaged motors and it makes no sense to prevent a car owner from bolting together a frankenstein if the parts fit.
The automakers are changing motors much more frequently than before. Today's racing Ecotec is not the same as in the 2015 cars. A top level spec salvage yard motor will cost more than a used up low spec motor but will be cheaper than rebuilding anything.
Our Illini group has been doing the D2 thing for 24 seasons and we've seen damn near everything tried at least once. The rules shouldn't keep people from being creative.