DIM Electronic Advance Ignition

You can reduce the effort required by starting with a Lean Burn distributor, which contains no flyweights, has no vacuum advance, and has locked/fixed advance (and more room in the distributor to add whatever you might be adding). Another advantage is that the Lean Burn distributors are in much lower demand than the advancing types, so there are mountains of NOS items available inexpensively. I know Old Car Parts Northwest has lots of them and would probably make you a juicy deal on one or more. They come in single- and dual-pickup versions; if you're putting in your own optical or other trigger, it doesn't matter whether you start with single- or double-pickup distributors.

Please keep us up to date on this...seems to me whatever you come up with would be readily applicable to small and big V8s and slant-6s as well. Please do take a look at the "how/why it's better" links off the HEI upgrade page and comment on how your circuitry will perform vs. HEI.