Just another thought.
From everyone I've spoken to the Ford electronic dissy does a great job - pick one up cheap too. They're a piece of cake to wire up to your MSD ignition. I have an MSD Digital 6 plus and a standard electronic Ford (Bosch) dissy on my XD.
Here's a link below (to another cleveland forum) reference getting rid of your vacuum advance. You can either just take the hose off and plug the hole or remove the whole vacuum diapragm unit on the side of the dissy and ensure you lock the moving parts for the advance inside.....the link explains how.
I was going to get an all bells and whistles MSD Dissy - it would be nice - but you don't need too.......not revving to 10 grand are you!!
You running and old or new cleveland block?....just making sure you're aware of the different size dissy holes in the block.