still not clear on- do all the cables have to be the same gauge? i just wanted to order garys h/o battery cables for h/o alternators would those gauges NOT be ok for the big 3? and would those hurt my 140 amp alt if i install them before i get my h/o alt?
I'm not sure I understand your question(s) in your post, but will take a stab at it.
The Big 3 cables don't ~have~ to be the same gauge, but why not. You'll be getting one length for the ground (-) approx 5' MAX (Cutting a 3' piece for the GND from the engine block to radiator support, and using the rest to go from the battery to radiator support which you'll prob have to cut down in length from the remaining 2' to have a nice fit), and then one for the 12VDC from the alternator to battery (+) 3' MAX.
Gary's cable's are a good upgrade, they'll go great with the Big-3.
There's no possible way upgrading to a heavier gauge would hurt the 140 Amp alternator.
Hope this helps.