Originally Posted by MountainBikeRoamer
If you’re going taller (putting in a lift), you ideally want to take as much advantage of that extra height as you can by having **longer suspension travel.**
With a stock-length radius arm, if you increase the suspension travel you also dramatically increase the change in steering caster angle as the suspension cycles through its full travel.
With a longer radius arm, you get far less caster angle change as the arm swings through the same amount of suspension travel up/down.
So unless you are lifting the van a good 4-6”, there’s **no need to have longer radius arms** (as the stock arms keep the caster angles within a reasonable range as they cycle up/down through their full suspension travel.)
Take a look at highly-modified off-road race vehicles....the ones with long-travel suspension have long suspension arms. But then look at a road racing vehicle, they usually have comparatively short suspension arms. (As the travel is much shorter and there’s no advantage to adding lengthy arms and weight.)
Hope you don't mind me chiming in here with some questions. I've been considering a lift/performance suspension kit. If the 4" Grocery Go getter from Weldtec is the one, would there be any benefit of going with the extended radius arms or is it not needed then since the lift is minimal? Looking to run 285's and get the full performance 4" setup with the leaf springs, call De7aver tomorrow to see what they could custom make and cost, the E350, 7.3L carries a bit of weight back there! Thanks for everyone's input and questions here- Great read through!