[DougD]

Originally Posted by Randy Rosenberg

I'm no expert here, but there seems to be a lot of discussion on the internet (google: ported vacuum advance) about whether to use "ported" or "manifold" vacuum for ignition timing advance. From what I read briefly, you need to determine which is best for the tune of your specific engine. I suggest you do a bit more research to determine from where to access vacuum for your ignition. Also, I don't recall you saying "why" you are swapping out your mechanical-only distributor for one with vacuum advance.

Randy
I'm swapping for a several reasons - including reliability, maintenance, replacement parts availability, and driveability/mileage. I bought the MSD because I didn't think I could afford (or find) an original 427 distributor (I know they weren't vacuum advance) and because I didn't know that the Duraspark would fit. My car's not a race car, and spends way more time cruising on the street than at the track.

My research concluded that manifold vacuum is the way to go.

Rick
That won't be a problem. My engine is slightly lower in the rear.

Doug