Transit custom

Hi, would greatly appreciate some advice. I have recently purchased a transit custom crew cab swb 290. I'm currently towing my swift conqueror 645 and have read about people adding a shock link to the towing vehicle to absorb the load due to the spring leaf suspension.

Does anybody towing with a custom or a vehicle with spring leaf done any modificatiions to the vehicle?

I'm seeing more and more customs towing caravans and concerned if there is something I need to add to mine like the dixon-bate shock link?

Thanks in advance, any feedback would be greatly received. 

Thanks kevin