Are these the only batteries you have, or is there one under the hood still? 1 gauge its pretty light for starting the engine from that distance. I would have gone at least 1/0.
When I relocated my battery, I ran a cable from each battery to the starter.

those are my only batteries. like i said if i have a problem with it then i will upgrade. i was looking at 1/0 and somehow they talked me out of it. as far as hook up it's like it shows in the pictures. pos./ neg. go from the DS battery and runs to the PS battery and then to the starter. the neg. goes straight to the engine block. now if i have to upgrade cable size can i do only the pos.? or do i need to do the neg. as well? where did you put your batteries?

Mine are still under the hood, I swapped air cleaner and battery positions. Each battery has a cable from positive top the starter, and negative to the block. All 4 cables are 1/ 0.

If each battery had one gauge from it to the starter, it would be better. Right now all that available 2000cca can go through one, one gauge cable. Ground its more important that the power wire, and it should be the larger off anything.

If it does become a problem, I would try this set up. 1 gauge from each battery positive to the starter. Then add a 1 gauge wire from the ground to the frame, along with the current 1gauge to the block. This should support the loss, and cost less than buying 1/ 0.

ok. do i need to run a ground from each battery to the block or can i get away with the one?

I suggest one from each.

ok. should i do this one out of 1/0 so i don't have to upgrade later?

If the distance is less than 9 feet, 1 gauge should do the job.

i'l have to measure it out. 2 feet behind the cab to the front of the engine. might be longer than 9 feet

Interesting.

I could not stomach the 1k, but I like the idea for the space under the hood.

oh believe me, i turned my head as he swiped my card. i want to put the water meth tank in one of the battery trays under the hood. if they make a tank that small that is.