one problem i had with my 110 tray is that the rear tyres (255/85/16 on offset disco's) hit the tray under articulation big time.
i eventually put wheel tubs in the tray to allow 50mm more room.
i could of lifted the tray but it would have been ridiculously high.
i think defenders have a low c.o.g. allready and this is a good thing to keep. i see some hiluxs around and the trays are so high the side slope ability must be compromised.(especially with camping gear or tools aboard)
also try to make use of the wasted space underneath.
i believe you can also fit a long range tank at the rear and lift it up higher because of the space between the original tank and the tray.
this would keep a stock departure angle with a long range tank.
david
(i'll try and think of more tips, i've imagined rebuilding my tray MANY times)