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Long story short, I think I need to buy springs but don't know which ones to select. RockAuto has 27 different "GM Genuine" coil springs for a 2017 GMC Sierra with 6.2L engine. I am wanting to match the spring rate of a 2017 GMC Sierra SLT CrewCab 4x4 6.2L. If someone has this exact truck, maybe they could post their RPO codes please? Or maybe, hopefully, someone has a better idea to get this info? The long story (if you care to read on) is I have the 2017 GMC Sierra Denali CrewCab 4x4 6.2L with MagneRide shocks & struts. The truck has just under 60K miles and the ride quality has degraded over time. I know at least 1 shock is bad due to it leaking, no codes have been thrown on the dash. Due to the mileage and the expense of the MagneRide shocks, I am pursuing replacing them all with conventional shocks and at the same time, getting my truck level. Several options on the market claiming great ride quality but I'm leaning towards the Bilstein 5100's that I've had on past trucks or the Eibach ProTruck kit E80-23-006-02-22 for $704 that sound great too but I'll need to buy strut mounts and deal with compressing those beasts (others have had issues). Or possibly the RoughCountry E2 loaded struts #501029 - inexpensive but not sure on ride quality + reliability or maybe even Fox 2.0's if I can find them for a good price. I would even consider the Belltech coilovers #15102 for $650 /pair if I could find someone running them with a positive review. If/since my MagneRide coil springs aren't the same/compatible, with some kits including the Bilsteins, I'll need to buy new springs, which isn't a huge deal since they aren't too expensive - some as low as $34. I know Eibach's kit comes with springs included but it appears they have a higher spring rate for trucks with extra weight on the front of their trucks. Of course, I'll need to deal with the MRC electronics, cheapest I've found is https://www.magdelete.com/collections/sierra-1500 and I may end up just getting the entire kit from him but don't know which springs are used with his either... It does make some sense that there are so many different GM Genuine coil springs due to there being 3 different engines available, 3 different cab sizes and 4 different trims... I do zero off-roading or towing and am just looking for a nice street ride with a leveled look. I welcome input on anything I've said but I'm mainly looking for the proper conventional OEM spring that will match best with my truck.

This has been an on-going research project of mine. I discovered when I inquired about having the Trail Boss (TB) factory lift kit (GM part# 84629787) added to my 2019 LT Z71, that I could not have the kit installed due to the secondary composite leaf springs on my truck. Upon further investigation, I found that ONLY the LT with 5.3L (and LT with 3.0 diesel and short box) had the composite leaf springs preventing the truck from having a TB lift added. On the GMC side, I found out the Sierra Denali also uses the same leaf springs with composite secondary as the LT 5.3L. My first impression was, “why the heck would GM do this?” Why wouldn’t the LTZ or High Country (HC) have the the composite leaf? Why would only the mid-level LT have it? The Sierra Denali has it and it’s a $60K+ truck. My LT averages around $45K. I might be a little upset as a LTZ or HC owner to find out my rear suspension is the same as on any Custom trim truck, or even, the base W/T model. I’ve doing a lot of reading on composite leaf springs and there are more advantages to them than disadvantages. Though they are dimensionally bigger (thicker) than the steel counterpart, they weight a lot less, last longer, and offer better damping properties than steel. GM has had a good track record using composite leaf springs. The same technology has been used on the corvette since 1997 with the introduction of the C5. Disadvantages are minimal, such as, they are more expensive to produce, can burn up in a fire, and in this case, can’t be further bent or altered out of original specification. This must be the reason GM won’t allow the lift to be added to vehicles with a composite leaf. I’m sure the leaf could take the additional stress, GM engineers just want to play it safer than sorry. So with this, the Silverado LT 5.3L (and LT 3.0 diesel with short bed) and the Sierra Denali are the only trucks to use the composite leaf. Though I’m disappointed I won’t be able to get the TB lift added, I’m now pretty stoked to find out my LT has more mechanical innovation put into the suspension and I didn’t have to spend $15K+ more for a Sierra Denali to get it. However with this, it seems that if someone is looking for a top-end truck, the Denali would be the better choice over the HC which lacks the particular composite leaf spring feature, if that mattered to the buyer. For reference, attached here are the GM compatibility charts for the Silverado and Sierra to see if you can add the TB lift kit. Also here is a link to the previous discussion about the TB lift kit where you can find more detail about installation and issues surrounding the composite leaf springs.