Ignition Starter wire

[RBuhr69]

Can anyone tell me what size the AAW or Painless is using for the ignition wire to the starter for a 69 Camaro? I keep having an intermittent starting issues to where the starter does not engage all the way occasionally(hits flywheel and does not engage). I have been told by several sources (including vendors) if it is intermittent there is a voltage issue. I have replaced the starter (different brands), all new battery wiring pos &neg, made sure all the grounds are good and a new Optima battery with no luck resolving the issue. This is on a new block and I have even gone as far as repalcing the Flex Plate.....

The only item I have not replaced was the wire from the ignition to the starter and need to know what to change it out to as my sources are all over the place for suggestions.

Thanks in advance....