i can imagine the compressors working lose then a big flyin syncro spring making a right mess of me hair
So can I so if you try again, tie a few loops of polyrope around them first as final safeguard?
Standard springs and a 1" spacer might up top be sufficient...
With your use you need good condition or heavier duty shockers (def. with synro springs) and always make sure your rear tyres are up to pressure, even a couple of psi above, measured cold, as long as you don't go over their max pressures.
With 1 ton in the back of my Doka syncro, I knew imemdiately I had to drive very cautiously; brakes, steering and performance were all seriously impaired.