Ignition Control to Distributor

I am not so sure one leg of the p/up coil is grounded. If this was the case, the grd wire could be grounded internally in the p/up, & only one p/up wire reqd to connect to the ECU. A saving in money. Grounding through the dist body is not a problem, the GM HEI grounds the coil through the dist body, & a far higher current than the p/up generates.