For a single coil distributor, just use a single BIP373 internally. See
this link to the Extra manual for an idea on how to do this. I couldn't find similar instructions in the MegaManual for use with the V2.2 board, but the only real difference I see is to connect the 330 Ohm base resistor to JS10, instead of R25.
You can get the parts you need from DIY Autotune;
they sell a kit with everything you need except the heat sink grease. Be sure to deburr the hole in the case carefully, as small burrs poking through the hole in the insulator and causing a short is a common problem.