Engine blueprinting means specifically to create an engine that reflects the design intent through the removal of manufacturing tolerances insofar as that is possible such that the engine literally reflects the actual blueprint created by the original engineers who designed the engine. While many people confuse blueprinting with high-performance engine building or tuning, these are in fact different goals.
Rebuilding an engine to perfect tolerances.
The only things that you declare to Insurers are things that they'll find if you end up claiming. Be it an accident etc!
They'll never know you blueprinted an engine, and quite frankly.. even mentioning it is a recipe for disaster.
I declared my Eibach Springs, and Enkei 17" Track rims to Admiral insurance the other week. They told me they'd be unable to insure my car as a I go on track!
I told them it had nothing to do with them, and that I was only insured with them on the road. But they still refused!!
Would it be fair to assume that any advantages of blueprinting would be less pronounced on a modern engine, given the tighter manufacturing tolerances that modern production techniques can produce?
I fell for a similar trick. Insurers have no right to tell me what I can and can't do with my vehicle with off public roads, I won't be using a company like that again trust me!