The FSM lists the US spec coil resistance (in the 1980 FSM) as 0.5-0.7 Ohms and the non US (FS and General) spec as 1.2-1.5 Ohms. PerTronix lists their "paired" coils for the PerTronix 91662LS as either 1.5 or 3.0 Ohms.
Was the OEM spec based solely on the points installed, or something else...