to be honest it doesnt matter as long as the 12v is correct to the msd. it is the larger of the three wires as well as the middle one and you have the same channel 1 going to the msd is the same as channel 1 coming out the car will run fine. even if you get them mixed up and wire it backwards so to speak it will run. if it wont crank, then just switch the two outside wires around at the coil plug with no harm done.
as far as the where to mount it, you will read a lot where the msd has failed when mounted in the engine bay because of the heat so i mounted mine under the passengers seat and then ran the wiring under the carpet. i then mounted the stutter box switch inside the ash tray compartment
