Battery cable gauge and length

[oldmopar]

The larger the better so if possible try to get a 1 or 00 gauge cable. It also helps if you relocate the ground closer to the starter

[John Hendricks]

I don't know about the length u need, but the gauge is #2-the one that is the size of your thumb. NAPA stores can make any length u need on the spot.  They have a little tool they hit with a hammer to attach the correct ends.  U might want to consider using a second ground from the motor to the frame-one of those flat woven ones will do.  seems to make things work better, and with a pos ground, corrosion is more severe on the ground end.  I don't recall the physics of why that happens ,but it is one of the reasons folks think 12 volts is better--just keepthe ground clean and things will work just fine for 6 volts.

[Bob]

I need to know the correct length and guage of the battery cables for a 1940 Plymouth, I know it has been mentioned before on the website, but was unable to find it.
Thanks in advance,
Bob