A basic questing, what is blue printing of an engine,and what value is it??

Blue printing is a pretty broad term. The basics of the process are simply a much more precise job when the machine work is done. Things like align hone of the main caps, squaring the deck of the block, spin balancing the crank, port matching the heads and intake, etc.
I'm sure others on here can add to the list.
Depending on what you are trying to achieve, some of the work is expensive and unnecessary on a street motor. A good balancing job is worth the extra cash and can add to the life of the motor.

I can add many small details, but that's what blueprinting is. Exact detail to everything. Normal mfg makes things within specs. Blueprint makes it all match. No a street motor does not need it.

But it will make any motor last longer, run smoother, and perform more evenly between cylinders, which always helps performance and economy. It also allows the engine to rev higher. It's a very good thing.

But also more expense than is necessary for most of us. Other than spending cash, you can't go wrong. Do you need to be that right? Maybe so.

Blueprinting an engine came from drag racing. Blueprinting optimizes each cylinder by making each
combustion chamber exactly the same volume,indixing the spark plugs so that the ground electrode on the plugs
all point in the optimum position,etc This was 1970
when every car ran a class instead of ,run what you brung
bracket racing ,like they run today. Back when you ran
classes someone always had more money to spend than you
did and those cars won.Bracket racing levels the field-
mutch better. If you want a hot street car you can
probably install a blower for less money than blueprinting!
Steve