Help with my duraspark conversion.

I need help setting up a duraspark II distributer with a msd 6 box in my cleveland. I plan on going to the local autozone for the dizzy but I need to know which vehicle I can match it to. Most times the kid behind the counter doesn't know much besides what is on the screen in front of him and I know if I go ask for a duraspark dizzy for a 351 cleveland he is going to have trouble with it. Gotta give the whole "year/make/model" b.s.

Also, do I absolutely need the harness or can I just make my own?

Thanks,
Josh

Thanks! Thats exactly what I needed to know.

I can get the wiring diagram off of mustang steve's site.

Any regets with going with the duraspark?