Re: what does Blueprinting an engine mean?
Blueprinting is just that, making an engine exactly like the blueprint, with much better tolerances than the typical production line.
CC'ing combustion chambers so they are all exactly the same, making sure bearing clearances are all perfect, ring gaps, piston clearances, etc, etc.
And engine will be typically be smoother and run more efficient when blueprinted, and it is mainly required if it's in a high state of tune.
A standard engine will likely not benefit much (if at all) from blueprinting.