Hi. I'm finally back to work on my project, but I am unable to set the timing where it needs to be because the vacuum advance module on the distributor hits the intake manifold and I cannot advance it enough to make it run properly. Do I have to go to a mechanical advance dist or can I make this one work somehow. I'm running the summit distributor and the Holley Dominator Dual plane. Thanks

Pull the dizzy and put it forward 1 tooth, then you won't have to twist it as far to get the timing you want.

You want to move the shaft clockwise one tooth so the housing moves clockwise with it, and you can then rotate the housing counterclockwise to advance the timing w/o hitting the intake. The oil pump shaft probably won't line up when you do the one-tooth move thing, don't worry about that just set the distributor in, let it rest there, and bump the engine - the distributor will drop down.

The Summit distributor is a mechanical advance distributor. It has a vacuum advance as well (as do most non-CC distributors).