never seen one of these...

I think the eccentric is the RPM advance adjustment. Looks like you turn that to adjust the tension on the spring and that would raise your RPM advance window. Like putting heavier springs in your distributor.


( I wrote this hours ago before the instructions were posted, just never sent it)
PS> note the mention of a silent chain being used instead of a double tooth loud "truck chain" as the varicam absorbs the shock that wears out silent chains.