[David Pozzi]

Here's my cheat sheet for PSIA to Vacuum conversion.
On this one, I was trying to leave 4 deg more advance available in software so I could try adding more later without having to re-set the distributor.
Another good trick is to set up the retard wire to a rocker switch so you can pull out 2 to 4 degrees if you ever get some bad/low octane gas and hear pinging.
I mounted the MSD in a place where I couldn't see the L.E.D. but found a fiber optic flashlight extension and used that to "pipe" the light to an area I could view it.