[Cobra 29]

I am running a 351W FMS crate engine and I believe it does have a quicker part trottle response and mileage with the vacuum advance. Just like Mr. Fixit points out the issue is limiting the vaccum advance module and thus the total degrees of advance. The initial and mechanical are easy to limit.

I have 12 degrees inital + 25 in the MSD mechanical all in by 2500 RPM but my vacuum advance module will apply 12 more degrees. While I do not hear any pinging (how???) this is about 49 total degrees at part trottle above 2500 RPM. I was able to limit about half the vacuum module's throw crudely by making a sleeve that limited the arm travel to the rotating distributor plate. My design is not easily adjusted!

Who makes a vacuum advance module where the THROW is adjustable? The Crame Cams unit I purchased limits the spring tension thus required vaccum amount to pull the full travel. Will the "adjustable" Accel unit truly limit the throw or just the amount of vacuum required like the CC unit? MSD should make such a unit given the expense many of us have in their total systems.