Hi Wayne,
What model GS's are you talking about? I assume since you are talking about fuel range you have standard GS's not GSA's? I've done a bit of that sort of riding and there's a few things I'd not leave behind.
I assume you are heading out in winter? We did a run through there last June to ride the ferry across the Cooper (3 GS's - 2 x 800's and a 1200 + a DR).
I would always carry
camping gear/water/food just in case something goes wrong and you are stuck beside the road for a few days. You should have no problems with humping that on a GS. We camped the entire time - came across the
Dog Fence from
Hungerford, through
Hamilton gate across to the cut-line, then
Tibooburra to Camerons, up from Camerons via Epsilon and the top of the
bore track (bottom was still closed) got fuel at Innaminka and then did the run to
Birdsville via Dig Tree, Arrabury, Haddons Corner and Planet Downs since it was too wet to cut across. The bit from Innaminka to
Birdsville is still only about 600km from memory. We each used a 12 lt fuel bladder to cart the extra fuel (these are a good idea since you can roll them up when you don't need them).
I can't comment on roads since they'll be different when you go.
Worth looking things up on the ADV rider
forum as
well.
Hope this is some use, message me if you want more info.
Cheers Nip