I recently installed an Eibach stage 2 lift kit leaf springs after about 6 months of research. I was actually perfectly happy with stock height but one of my leafs had flattened out to the point that you could noticeably tell by looking at the truck and it was effecting the alignment adjustments. Initially I had looked at getting stock replacement leafs but ended up going down a rabbit hole and learned more about leaf spring manufacturing and distribution than I really cared to. In hindsight, a set of 2 inch Dobinsons probably would have been fine OR I probably would have been happy with stock leafs and a set 4600s. However, I have no regrets with the route I went and have been really happy with how it's turned out.
A note on leaf springs....
General Spring sells a part number 90-297HD. That part number is actual a SRI part number. It comes from the Spring Research Institute (https://www.springresearch.org/_english/home.aspx) The SRI maintains a catalogue of spring part numbers along with specs. You can actually contact a spring manufacturer and provide them with a SRI part number and they'll be able to get the specs from the SRI catalogue and build it. The SRI also has a membership listing and according to the website full members manufacture SRI spec part numbers and are located in North America. Associate members manufacture or import part numbers but are not necessarily based in North America. The only reason any of this is relevant is that I was looking for US made springs with US made steel. Of the companies listed, Triangle Suspension and Standens are the only two that manufacture this part number with US steel. When you look up a 90-297HD you'll most likely find a spring made by Dayton with it manufactured in Indonesia. There's also a company called Universal Group that distributes this part number under various names and are imported as well. Dayton generally has a good reputation in the medium and heavy truck world, but I really just wanted US made leaf springs. I ended up getting mine from Rush truck parts who ordered it from a Triangle distro center that had them in stock.
The 90-297HD Specs -
Pad Thickness - 1 3/4 inches
Arch - 6 1/2 inches
3/1 Leaf Set Up with 3 leafs at 9mm and an overload leaf at 18mm
Compared to Stock Leafs Specs
Pad Thickness - 1 5/8 inches
Arch - 5 1/4 (measured 4 1/2 on the side that was flat)
3/1 Leaf Set up with 2 leafs at 8.5mm 1 leaf at 8mm and an overload leaf at 14mm
Rear measurements from center hub to fender -
Stock Springs
Passenger - 22 1/4 inches
Drivers - 21 inches
90-297HD
Unloaded
Passenger - 23 3/4
Drivers - 23 3/4
300 lbs load
Passenger - 23 1/4
Driver - 23 1/4
530 lbs load
Passenger - 22 3/4
Driver - 22 3/4
Front Measurements from center hub to fender (Measured 3 inches of down travel on both stock and Eibachs)
Stock
Passenger - 20.5
Driver -20.5
Passenger Extended - 23.5
Driver Extended - 23.5
Eibach Adjusted
Passenger - 22
Driver - 22
Passenger Extended - 25
Driver Extended 25
Installation Notes -
The Eibach kit comes with a sway bar relocation kit. You use the old sway bar bracket bolts to attach the relocation block to the frame and the new bolts go into the block. The instructions have you take the tie rod end and upper ball joint apart. I found it easier to take the tie rod loose and the two 19mm bolts that attach the spindle to the lower control arm without taking any of the ball joints apart. ******Torque the lower strut mount bolt with the suspension fully loaded with the weight of the truck. Drive the truck around the block after each adjustment to get the suspension to settle for an accurate measurement. Out of the box, they were set at 2 inches. One turn equals 1/8 inch of adjustment in ride height. You can also take an initial ride height measurement and then measure the spring seat to bottom of adjustment threads. Multiply the changes in the seat to thread measurement times 2 and you'll get close to what the change in ride height will be.
FREE ECSG REMOVAL AND INSTALLATION TOOLS!
For the removal tool, I went to O'reilly's and rented a pilot bushing removal tool. I already had the slide hammer but you can rent that too. It worked liked a champ getting the old needle bearing out and didn't cost me a dime.
I made my installation tool with two sockets, an18 inch piece of cast iron plumbing pipe and a cap. Find a socket that's slightly smaller than the ID of the ECSG bushing. Get another larger socket that's about 1/8 inch larger than the OD of the bushing. Place the sockets end to end where you insert the ratchet drive. Place the pipe cap upside down on top of the larger socket, then measure the distance between the inside of the cap and the inside of the smaller socket. Find a bolt long enough to bolt all three pieces together that will fit through the drive holes of the sockets and drill a hole through the center of the pipe cap for the bolt. Bolt it all together and screw the pipe cap onto the 18 inch piece of pipe. Now you have an 18 inch handle bushing driver that holds the bushing in place while you drive it into the differential.
Overall review of the set up -
The eibachs are nice. I'm probably not going to add anything that hasn't already been said about them. Highway and street driving is fantastic. It's planted and firm but still smooth over dips and rough roads at high speeds. They've been great on some light trails too, but I haven't done any high speed off roading and probably won't. I generally just end up going off road in the course of doing other outdoor activities. The rear springs are much more firm than stock but aren't a harsh ride by any means. They feel similar to every other half ton truck I've driven.
A note on leaf springs....
General Spring sells a part number 90-297HD. That part number is actual a SRI part number. It comes from the Spring Research Institute (https://www.springresearch.org/_english/home.aspx) The SRI maintains a catalogue of spring part numbers along with specs. You can actually contact a spring manufacturer and provide them with a SRI part number and they'll be able to get the specs from the SRI catalogue and build it. The SRI also has a membership listing and according to the website full members manufacture SRI spec part numbers and are located in North America. Associate members manufacture or import part numbers but are not necessarily based in North America. The only reason any of this is relevant is that I was looking for US made springs with US made steel. Of the companies listed, Triangle Suspension and Standens are the only two that manufacture this part number with US steel. When you look up a 90-297HD you'll most likely find a spring made by Dayton with it manufactured in Indonesia. There's also a company called Universal Group that distributes this part number under various names and are imported as well. Dayton generally has a good reputation in the medium and heavy truck world, but I really just wanted US made leaf springs. I ended up getting mine from Rush truck parts who ordered it from a Triangle distro center that had them in stock.
The 90-297HD Specs -
Pad Thickness - 1 3/4 inches
Arch - 6 1/2 inches
3/1 Leaf Set Up with 3 leafs at 9mm and an overload leaf at 18mm
Compared to Stock Leafs Specs
Pad Thickness - 1 5/8 inches
Arch - 5 1/4 (measured 4 1/2 on the side that was flat)
3/1 Leaf Set up with 2 leafs at 8.5mm 1 leaf at 8mm and an overload leaf at 14mm
Rear measurements from center hub to fender -
Stock Springs
Passenger - 22 1/4 inches
Drivers - 21 inches
90-297HD
Unloaded
Passenger - 23 3/4
Drivers - 23 3/4
300 lbs load
Passenger - 23 1/4
Driver - 23 1/4
530 lbs load
Passenger - 22 3/4
Driver - 22 3/4
Front Measurements from center hub to fender (Measured 3 inches of down travel on both stock and Eibachs)
Stock
Passenger - 20.5
Driver -20.5
Passenger Extended - 23.5
Driver Extended - 23.5
Eibach Adjusted
Passenger - 22
Driver - 22
Passenger Extended - 25
Driver Extended 25
Installation Notes -
The Eibach kit comes with a sway bar relocation kit. You use the old sway bar bracket bolts to attach the relocation block to the frame and the new bolts go into the block. The instructions have you take the tie rod end and upper ball joint apart. I found it easier to take the tie rod loose and the two 19mm bolts that attach the spindle to the lower control arm without taking any of the ball joints apart. ******Torque the lower strut mount bolt with the suspension fully loaded with the weight of the truck. Drive the truck around the block after each adjustment to get the suspension to settle for an accurate measurement. Out of the box, they were set at 2 inches. One turn equals 1/8 inch of adjustment in ride height. You can also take an initial ride height measurement and then measure the spring seat to bottom of adjustment threads. Multiply the changes in the seat to thread measurement times 2 and you'll get close to what the change in ride height will be.
FREE ECSG REMOVAL AND INSTALLATION TOOLS!
For the removal tool, I went to O'reilly's and rented a pilot bushing removal tool. I already had the slide hammer but you can rent that too. It worked liked a champ getting the old needle bearing out and didn't cost me a dime.
I made my installation tool with two sockets, an18 inch piece of cast iron plumbing pipe and a cap. Find a socket that's slightly smaller than the ID of the ECSG bushing. Get another larger socket that's about 1/8 inch larger than the OD of the bushing. Place the sockets end to end where you insert the ratchet drive. Place the pipe cap upside down on top of the larger socket, then measure the distance between the inside of the cap and the inside of the smaller socket. Find a bolt long enough to bolt all three pieces together that will fit through the drive holes of the sockets and drill a hole through the center of the pipe cap for the bolt. Bolt it all together and screw the pipe cap onto the 18 inch piece of pipe. Now you have an 18 inch handle bushing driver that holds the bushing in place while you drive it into the differential.
Overall review of the set up -
The eibachs are nice. I'm probably not going to add anything that hasn't already been said about them. Highway and street driving is fantastic. It's planted and firm but still smooth over dips and rough roads at high speeds. They've been great on some light trails too, but I haven't done any high speed off roading and probably won't. I generally just end up going off road in the course of doing other outdoor activities. The rear springs are much more firm than stock but aren't a harsh ride by any means. They feel similar to every other half ton truck I've driven.
