Defender 90 suspension mods...

Hi all,

Another suspension thread.... (don't get me started on tyres)

My 300TDI 90 currently has the following setup:
Front - NRC9448/9 springs (normal 90 rear, HD 90 front) with RBC100111 Disco2 rubber isolator cones
Rear - RKB101240/30 HD progressive springs with ANR2938 spring isolators.
Stock shocks and mounts all around.

Hub to arches:
FL- 535mm
FR- 520
RL- 525
RR- 500

Without a significant load other than me, the front shocks sometimes top out, as in over extend.
I'll mount an internal/external rollcage in a couple of weeks.
I'm installing 255/85R16 tyres on Wolf rims. My current 235/85R16 ATs on 16X7 rims nearly rub on full articulation. I might go for 285/75R16 somewhere in the future.
I'll travel to Africa in December for a 10000km trip with the usual long trip load, 2 spare tyres and rack but no roof tent.

I was having the idea of making more room for the bigger tyres:
- dropping the rubber isolators (- 10 or 12mm);
- installing +50mm bumpstops;
- installing +50mm spring spacer blocks (IMO no point buying longer springs if the upwards travel is limited by the longer bumpstops);
- installing rear shock droppers.

I'm essentially moving the stock travel downwards.
Does this makes any sense? Or am going to drop >€200,00 for some tyre clearance I don't need?
Is this a bad idea for expedition load and desert/dune driving?

Thanks in advance

Anyone?