blueprinted means the engine is built to certain specs, and in the cases of kart motors the engines ported and built to make more power, by flowing better, compression and a huge laundry list of things,
The only thing on the fun power engine that cant be blueprinted is the carb, It uses an air mixture carb rather than a fuel mixture carb, (to change the carb rich to lean) You could easily update that to a raptor or tiller carb and get more power.
You can get up to two horsepower just by reaming out the carb and doing work to it, I plan on getting a different carb this summer, I think mines choking out the engine a little,
The bad thing with kart engines is normally you loose the choke making starting a little more difficult, But oh well.
I like orange and black, or orange and red for color schemes, As you noticed im really partial to Ford Blue and White, Its my favorite to be honest, White doesnt like to stay white always, But I keep it clean and love it.
And even if I get a few nuts and bolts I get excited,
Its always fun
Heres an article on blueprinting the briggs flatheads
4 Cycle Karting Forums - FAQ: Flathead Blueprinting
More than alot of that information is probably over your head, And id recommend learning more before tackling big projects, I can help with alot of it, But even my knowledge is limited.
On another note 4cycle is a really nice forum, Except they dont like Minibikes at all and normally youll get all your questions answer but sometimes youll be stranded with no help and more confused than when you started,
Enjoy!