2013 2500 4.8
Hi I' bought a 2013, I'm going to do some preventative maintenance, like the tranni flush I've bought a Dorman pan with drain plug, coolant flush upper lower hoses thermostat, plugs and wires, differential fluid, engine oil and major rust proofing painting it black all this spring so I can go on long trips this summer!!
Can you tell me about the leaf springs on these vans this is my first car with leaf springs,

Leaf rear left
Leaf spring

Leaf spring
I think mine are a bit sprung, out of line
The bottom leaf is not inline with the rest sticks outward on one end and inward on the other.
Do leaf springs fail commonly? I bought the van used has 167,000km, was a work van,
Also if I do buy new ones can I get 4/1 ?
I think I have a 3main 1 helper
Rick auto has 4/1 5)1.. etc
And when I drive the van it does have a jingle sound going over bumps empty and I think it could be the suspension.