Securing Rolled Over Axles on a Tandem Van.... potential for cracked springs

Friend has a Tandem Van and wanted to increase the off road height. Rolled over the axles did all the required things now the springs are on top of the axles.

As you know with the springs underneath the axle, there is a plate and pin to centre the springs or such like, the U bolts go over the axle and springs to bolt to a plate underneath both the axle and springs.

I understand that the standard way of attaching the springs above the axle is to weld the centring pin/plate on top of the axle and put the plate on top of the springs (springs on top of the axle)with the U bolts being upside down. with this method I see a higher potential for breaking the top Spring.

Under axle setup: With the spring leafs fixed between the axle and the botton plate, large movement of the springs upward would put some pressure on the spring where it comes in contact with the 50mmx50mm axle/centreing plate. ie the pressure point on the spring is approx25mm from the axle centre.

With the 120mm x 80mm plate ontop of the axle, the pressure point on the spring is 60mm away from the centre and with movement of the spring there is a greater chance for it to break .ie less movement of the spring to apply the same shearing pressure

Of course this is all my theory which could be completely wrong,(and I am not a mechanical engineer) and thousands of vanners have rolled their Springs without problems.

I have seen the results of top broken springs on tandem vans, but both with springs under the axle, and with a ratio of 1000 to 1 or more(Under to Over) of course its the more likey outcome.

Comments appreciated.

Peter