I don't remember 100 percent but if y0u pop open your dizzy on your oem coil there should be a black/yellow 12 volt (+) wire and the other wire is the (-)All the wires you need for the install are inside the distributor.One of those wires I don't remember which,has two wires going to the stock coil so when you cut those from the stock coil solder them together.
The extrenal cap is like 25 dollars.The power tower terminal to moddify your cap is like 12,so I opted for the cap.Mine cost a little more since its hei style,which I like because theres a screw that secures the boot in place so they will never come loose.I also had to buy the super conducter wires and convert the boots to hei style.
edit: I found my msd cap instruction manual that comes with directions for an msd sci box but should be similar for a 6al
RED on the box is + to the battery
BLACK on the box is- ground
WHITE goes to the original coil-(trigger wire)(inside dizzy)
RED goes to the original coil blk/yellow+(ignition 12 volts)(inside dizzy)
ORANGE on the box goes to the new external coil +
the other BLACK on the box goes to the new external coil-