I've just fitted a new chain and sprockets to my 3tj. The bike is a touch higher than standard and this combined with it only having a 39 tooth rear sprocket had caused the chain to eat through the runner as mentioned in a previous post, Now In the free downloadable manuals it states 15mm - 20mm slack with bike unloaded on wheels but in the 92 3tj supplement it states 35mm - 45mm, Trouble is even at 45mm, when I sit on the bike and the swingarm sinks to what would be it's original factory position the chain seems to get really tight. I'm just worried that if I hit a bump or the supension gets really depressed that the chain could snap.
Should I get someone to apply a bit of weight to the bike and adjust the chain when swingarm is in original position or what?? Like I said it's not hugely raised, I think the holes in the doglegs are about 1/4" shorter than original. I just don't want to snap the chain or end up with it too loose.

Do it the way the manual says - I have a look at my chain, lift the bottom run to check and if it's "ok" I'm happy. It shouldn't be a problem

just make sure you dont have a really tight spot, if you do the adjust the chain with the tightest bit at the bottom.