Here is my 2c worth.
I have a W111 finny with 4.5 running gear in it - so it has the W108 diff and springs. My car sits too high. So I bought a whole W110 190D last weekend - it was sitting level with the correct camber.
So I removed the spring and fitted it to my finnie. The spring from the 190 was a different part number to the 108 one. I reckon the car may have lowered by 5-10mm, that is it. So it is still a tad too high. So all three springs must be controlling the height of the rear of the car - so I will need to swap the 2 trailing arm springs over too.
And here is how the 190 loooked with no compensating spring at all.
Lower than correct, though I quite like it. Can anyone tell me what would be the impact on the dynamics of the car if I did not refit the spring? Would it be dangerous to drive, or just lower?
It only took about 15 minutes to change the spring over. You jack the car up and put jack stands under there. Put a jack under the right hand edge of the bracket as shown below, slacken the left bolt a it and take out the right, then lower the jack. Installation is reverse of removal.
what would be the next thing to do? Where cutting, torching or locating weaker springs are not options.
If you rule out those options, then put 10 bags of cement in the boot.