Holley stumble trouble

Mattax said
The second spring should have a loop on one side. That length of the loop and the spring perches determine how many degrees into the advance before it starts to restrain the weight.
While we can't do this with many non-chrysler distributors, its not such a big deal when initial timing is around 20*.

What I'm saying is something like this would almost certainly be OK with vac advance.

And something like this almost certainly will not work well with vacuum advance.