slant six starting problems

You need 12 volts. Where there is a 4 post dual ballast resistor and 5 pin ecu, that ecu does operate on less than 12 volts BUT, the problem with resistors is their ignorance. If it reduces voltage by 2 volts, 12 volts in becomes 10 volts out. Logically 10 volts in would be only 8 volts out.
Where there is a 4 pin ecu that operates on 12 volts, it needs 12 volts.
The 10.7 at battery when cranking has me wondering... Is the battery is bad or just drained from repeated cranking efforts ? It aint 12 volts regardless. Is the starter drawing all the amps available from that battery ?