Base timing. Really ?
Guys im confused on why you say im better off without the limiter plate.
What I was trying to explain in post #59 is that the FBO plate's disadvantages are not your problem:
A. Your not using vac advance.
B. If the JBWeld was on the outside of the slots, then the FBO plate has the same effect on the weight movement as the weld.
My suggestions on what you should do next are in post 59.
I won't be around. I'm already running very late today so can't offer more than this.
If you want to understand the different effects of shortening the advance on the inside vs the outside, spend time looking at the the links above. As far as the heavy secondary spring for racing, do a search for some posts I made about the MP "Tach Drive" distributor.
Different people learn different ways. Another thing to do might be to open up the distributor and move the weights out to see how the spring effects the movement.
You might be best off just following the steps in post 59. Measure and plot out the timing vs rpm up to 3000 or so. Then mark where the problems occur. You can then figure out what to do to reduce the timing under those conditions.