Hotrodder

What good does a HEI distributor advance curve kit?

I understand the different springs. Those makes sense. But what's the point in changing the weights and centerplate? What differs the weights and centreplate in an aftermarket HEI distributor from the same parts in a kit?
I have a HEI distributor from Skip White on Ebay with 20 degrees of mechanical advance.
The Moroso curve kit I have ordered have 23 degrees.
Should I change to those, or keep the standard ones?

Engine is a 350 factory roller Block with Vortec heads modified for higher lift and a .500" lift cam with relatively small overlap to give good vaccum and good idle.

Vader

The curve cut into the inner leg of the advance weight (the business end) affects the rate of advance change, as well as the springs. A fairly regular curve can result in a fairly linear advance, whereas a modified curve will vary the rate of advance change at different RPMs. Ideally, a combination of high vacuum advance and centrifugal advance coming in at lower RPM/lighter loads, then a flatter area in middle RPMs, and a more aggressive curve at upper RPMs can be desirable.