hide the mad box under the battry tray.
connect the blue wire and the black wire lading to the ballast resistor. then use those connected wires for your keyed power lead for the msd.
then hide the 2 wires for the coil wires in the original harness back into the harness.
then hide the coil leads from the msd into the original harness.
install all of the original ignition components on the firewall.
your msd now works the ignition system without sticking out like a sore thumb.
if your msd ever fails you re connect the black and blue wires to the ballast. then attach the original coil wires to the correct terminals and now your original electronic ignition system will now work.

here is what it will look like.
unless someone looks under the battry tray and sees the red msd box, they will never know you are using a msd ignition system.