Going to be moving battery box to the truck.. what gauge wire?

[RM]

I'd go as big as possible. I've done several swaps like this in various
cars. You'd be surprised what voltage loss's occur after several years....
such as a 2-3 year old battery, a tiring starter, corrosion, etc... I think
the original starter wire was 4 or 6 guage. I went to a battery wharehouse
that has bulk wire and typically use either 0 guage or 00 guage. It's thick
stuff, but if you are going to allthe trouble to move the battery, why not
go big on the wire!?

Rolf Mair