The specs your looking for are the gaskets.The part that you want to port.
or bore out is called gasket matching
if you are wanting to bore out the supercharger plenum for a larger throttle
body.Take the throttle body gasket and put it up against the plenum end
that the throttle body bolts to.Then scribe a mark around the inside of the
gasket,then with a die grinder,in your case,you can use a drill with a small
tapered grinding stone in the drill.Grind allmost up to your scribed line.While
you are grinding up to the scribed line hold the drill 45 degree.as you grind
toward the scribed line.
The you will need a flap sanding wheel to put in your drill.Hold the drill
45 degrees,and finish sanding out to your scribed line.Only grind and
sand at 45 degrees,and about 3/4 of a inch into the throat of the plenum.
Thats it.
The way that you ask the question on how to do this,I don't think that
it would be a good idea to try any porting on your own.Or boring as
you put it.If your just hellbent on tring though, it may be a good idea
to have another plenum part lined up to buy.But ya got to start some where.
If you want to start porting the throttle body would be a good place to start.
Leave the intake and the exhaust alone don't doit. Don't touch them.
Good luck RANDY