Chryco,
I talked to 440 source today regarding the distributor "street distributor" I ordered from them. They said the RPM capabilities are around 6000. As for the ease of adjusting the advance curve, it sounds like it is very hard to change. Both of the 440 source distributors use an "ink pen style" spring. No parts are supplied with the distributor. Also the Pro-Billet distributor will not work with the factory electronic ignition system that came on the 73 Cuda. He said a more advance system (box) is need. They said that they are using the pro-billet distributor on the companies 512 stocker with no problems.
So this is what I'm thinking, since 440sources "street distributor" cost me $88 after shipping, and buying new pieces for my stock distributor would probably be around $50\60, I think I'll run this distributor until I rebuild the 440 this winter. Other Mallory distributors seem to run around 250 plus. My 440 runs strong but has a "knock" in it that I haven't found yet. I think it might be the wrist pin possibly.
If you have any other ideas let me know, thanks.