Electronic ignition upgrade

Compare the '70 timing specs to '68 or '67, probably similar = pretty good. I had good experience with '68 slant six milage and pep compared to mid '70s ones.
Agree the distributor pain to get to under there.
Guess it depends how many miles you putting on.
I think HEI is the best but not enough to outwiegh the others for what you want. In fact if I was in your shoes (and wasn;t staying with points) I'd be considering Pertronix because would keep the distributor. Any of them can die on you, HEI, Petronix, Skip White, Chrysler box...