I installed an MSD ignition system on my 91 305 TBI Formula and drew the four stages of schematic diagrams as I installed. Depending on what MSD components you are installing, you can choose which stage to use.
The schematics should be useful during installation and for troubleshooting, especially when you don't have to re-invent the wheel to determine how the ignition system is wired. I have noticed that some of the 3rd gen wire colors are different, so you may need to check out the wiring as you install.

11/25/2013
I have since updated the schematics, notes and added a second page for testing according to sheet 1 schematics.