In reality, I think there is far more adjustment on a PHR then you'd ever need. Anything up to a 3" lift doesn't even need PHR adjustment. So when you go the extra couple, there isn't much needed on the rod. Actually You'd think that someone would have come up with PHR correction bushes! You adjust it with the vehicle flat. It's not really about it being loaded. But you certainly don't adjust it with any droop. That would be extremely difficult. The best thing is cranked arms probably, but I have no idea if anyone does cranked arms for the 80 like they do for Landies. 5" is too much for CC bushes. There are some stories surrounding CC bushes too in that they promote cracking in the arms. I don't know if it's true, but the best way for bushes to work is for them to be central in the socket of the arm. I slotted the holes in the axle and welded plates on for the first lift and that was spot on. It wasn't far off being enough for this extra lift, but the plates are a good solution. It was no trouble cutting off the plates that I had welded on. Measuring left to righ correction for the rear PHR was easy, but trickier on the front as the wheel steer - obviously, so getting a datum wasn't easy. Found one in the end and adjusted up t that. By eye it looks right. Deff looked a bit over to one side to start with.
Chris