Would someone please help me understand how my distributor achieves it's "total advance".

I understand that the mechanical advance works on centrifugal force and the spring strength determines rate of advance. I also know that the distributor has a stop-point for mechanical advance.

What is the total degrees of mechanical advance possible, from TDC, in the GM stock (1977) HEI distributor? In other words how far will the mechanical advance turn before hitting the stop?

What about the Vacuum advance? Does the "mechanical stop" of the distributor also limit the total advance of the vacuum system as well? Or are these completely independent of one another?

I ask these questions because I am in the process of replacing a set of pistons. If you think detonation can't happen to you....

Thanks for any help

Colin

When I started my rebuild I wanted to learn about the inside of my engine. The price of this education is cheaper than college. I'll keep reminding myself of that.