I think you want to consider taking a breath here and first sort out your baseline timing, what the mechanical advance actually is on the distributor you have in hand before you start swapping parts. Is there a delco number or some other identifier on the distributor? If so, that is the place to start. You can figure out what year and application, then the stock specifications. From there, you can decide where to go from that point, i.e., advance starting earlier, or start at stock but all in earlier then stock, lighter springs, modified profile on the weights, combination of both. Frankly, this is best done on a distributor machine to really get it right.
Give some consideration to removing the distributor and sending it out for testing and recurving. Pat Mason, Mason Racing Ignitions in Ottsville, PA worked at Vertex magnetos for a lot of years. He builds and rebuilds all kinds of ignitions, including vintage Mallory ignitions. He is excellent and reasonable. I was just at his shop last weekend dropping off my Vertex for a little check up. You might consider sending your distributor to him and tell him what you are looking for, and then let him set this thing up for you correctly. I think you will be way ahead if you do. Just a thought anyhow. If you are considering sending your distributor to him, call as he is old school, extremely knowledgeable, and a decent guy to boot.
http://masonracingignitions.com/
