MSD install with out external coil
The first step would be to take the distributor apart till you get to the ignitor. Note some of these pictures are from an external installation.
Disregard the white wire that is from another install for now.
Next step is to remove the plug that connects to the internal coil
As you will notice when you take your apart there will be a tab that is connected to the ignitor. The tab must be cut from the center plug and moved to the end. I could not seem to get the wire soldered correctly so I just made a wire that has a ring terminal and soldered it to the correct position. This will be your new connection to the ignitor which basically your trigger wire for the MSD and just picks up your Rpm for your tach. It is connected to the ignitor where the white wire is connected in the picture of the internal of the distributor Above. Once installed back into the distributor you are finished with that part of the install and can reassemble the distributor. NOTE make sure that there is proper clearance on the ring terminal and the metal pickup that spins around in the distributor. It will cause your car to miss if you damage this part. I speak from experience. LOOK
Next step is to modify the pig tail that attaches to the plug. I put a water proof two pin plug that I got from Auto Zone a local parts store. It cost me about Three dollars for both male and female ends. There are three wires that need to be cut one is a Black/Pink the other are the Yellow/Black, Yellow/Blue it is hard to tell which is what color. Make sure when you cut the wires that you leave enough to solder some new ones on. Also do cut them to long as you will be attaching wires to the other end.
Here is an example of my wiring.
OK here is the fun part Soldering wires it is not hard but it is a pain in your Ass trying to hold Two wires at the same time heat them and the apply solder to them with out messing up. That is where my RC Cars came into play I have had much experience with soldering wires together. So lest start with the wires and what they are. Looking at the picture above going left to right first wire is Yellow/Black which is the Black Negative coil wire from the MSD. Next is the Yellow/Blue which is the Tach wire and the MSD input. This wire will need to have two leads that come off of it one that connects to the White wire of the MSD and the other that goes to the Factory harness I will talk about that at a later time. Final wire on the plug is the Black/Pink this is your positive lead to the coil connected to the Orange wire on the MSD. That is about it on the plug end.
Now lets discuss the wiring on the Factory harness.
On the factory harness you will only be worried about two wires the Yellow/Blue, Black/Pink. Be very careful which wire you choose it is very hard to differentiate the two Yellow wires. The Black/Pink wire is your ignition on and is connected to the Red wire from the MSD. The Yellow/Blue is for your Tach and is Connected to the other side of that Y you put on to the plug. The other yellow wire I just used some shrink tube and seal it so there would not be any problems with it shorting out. That is just about it for the install except for the Power and Ground for the MSD. I connected the Power which is the Heavy Gauge Red wire from the MSD to a power source. I used the fuse panel under the hood for that power source The Ground I put to Chassis ground. If you look CLOSELY enough you will see the connecting points of the Ground and the Power wire. I put a fuse in line of the Power wire for extra safety. And that is it. Sounds easy doesn't it took me about an hour and a half to install the MSD itself. I will take you about Four hours depending on you placement of the UNIT. I say this because I mad an Aluminum Bracket above the Transmission for it to sit on. See Below that alone took almost two hours of fitment to get it to sit just about right.
I choose to put in the water proof ends on the wires for the reason that I knew that I was going to do an external mod later down the road. Made it much easier for me when the time came.