I have a 2500 ST (tradesman) crew cab 4x2, with the cummins.

I noticed that my truck sits a little lower than my friend's '13 1500 does. They are both stock and both with 17" wheels. I then noticed that my truck seems to sit lower than a lot of trucks with 17" wheels.

I thought that odd, given my truck is supposed to have a much higher payload than the 1500. I looked at the RAM payload calculator and noticed a couple different max payloads for the various model trims of the 2500. I have the base trim, yet a couple of the higher trim levels (read heavier) have higher payload than mine… I began to wonder if there were different coils/springs used that affect payload and height.

I looked online at a parts site and noticed that for a 2013 RAM 2500, there are (8) different front coil springs listed. They are all for two wheel drive and are identified by three letter codes. I don't see any of these codes on my build sheet or window sticker…

coil spring Ram 2500; Code ZFK, ZUK 2WD

coil spring Ram 2500; Code ZFG, ZUG 2WD

coil spring Ram 2500; Code ZFH, ZUH 2WD

coil spring Ram 2500; Code ZFF, ZUF 2WD

coil spring Ram 2500; Code ZFE, ZUE 2WD

coil spring Ram 2500; Code ZFD, ZUD 2WD

coil spring Ram 2500; Code ZFC, ZUC 2WD

coil spring Ram 2500; Code ZFA, ZUA 2WD

These different coil springs retail from $127 to $195

My questions……..

Does anyone know what these codes refer to?

Could I raise my payload/height by adding a different OEM coil spring to the front end?

Thanks in advance to anyone who may have had experience with this….