Here's my solution for replacing a PS30 Stock CDI with a Pertronix HP box, using the stock harness hookups. It fit neatly on the existing bracket, with the aid of a pair of "hold-down" fender washers.
To get the Tach to work, I used an MSD Tach Adapter, as I could not get the Tach to respond to any alternate configurations using just the Pertronix setup alone. The Tach loses accuracy as the RPMs increase, with a 700 RPM difference at red line (reading 6800 at 7500 RPM actual) but for now, that deficiency will have to suffice.
The other change I made is to remove the in-line coil resistor from the circuit, which is a simple matter of removing the electrical tape, removing the 8" wire connecting the resistor and the coil, and storing it for later use if needed. I'll probably just mock-up two dummy wires and re-tape it to the main harness to give a stock appearance. Of note, I think one can hookup the stock distributor trigger wires as well, but a prior owner had removed a good chunk of the wiring already, so I just used modern purple/green wires, bypassing the harness hookups.
edit: in thinking a little about this tonight, I may consider adding a jumper to "Ign Start" to the +12v switched input of the Pertronix, and monitor the results. The car starts fine without this feature, but it's a little awkward, as some power is disabled during cranking (by the design of the ignition switch), which causes the Tach to jump twice.