ok so update time. after a couple months of getting things together to 4 link the van, I made an epic discovery that meant I could mount the particular g series diff that I have into the van with out having to fabricate anything.
So this is how I mounted the diff, I discovered that a 1966 hr series holden diff plates are about the right size to fit the hilux u bolts through and also fit the standard shock absorber.
the diff I have is from a yn85 hilux and is 1440mm wide, I have no idea if other diffs fit like this as ive never seen one. also other make and model cars may have plates that fit like the hr ones do.
I had to drill the holes out a bit bigger to suit the larger hilux u bolt.
then I fitted them on to see how that looked
as u can see, the diff plates fold up the side of the leafs making the ubolts to long, I made some spacers to fill the gap, but u could source shorter ubolts from somewhere or keep cutting the thread further up the u bolt if u had a die set.
now there is a mount to fit the shock just like factory, repeat for both sides and ur g series diff will be mounted with out having to fabricate anything.