Greetings everyone. I have the Eibach Pro Truck Lift System (Stage 1) on the highest settings (2.75" front, 1" rear). I purchased a C4 lo pro bumper (75lbs) and Smittybuilt winch (67lbs) recently and was wondering if anyone knows whether or not the Eibach springs I have will support the new weight without sagging or if I will need newer/different springs.

The lift has been on the truck for about 1000 miles and sits level, which of course, is the stance I'd like to keep. Thank you for any input you can provide.

I just finished installing the Pro Truck Stage 2 system on my 2018 TRDORP. I went with heavier springs on the rear when I bought this kit. I have a low profile bumper similar to C4 built by Artec, and a Harbor Freight winch, and I got 1" of lift on the front and 1-1'2" on the back (I had leveled my stock front before this, so those numbers started out with a level stance) right out of the box. I'm not set up on the highest for the front, I have room, but I am allowing a little rake so that when I load up it levels out. Plus, honestly, it looks good with a little lift and still raked.
Does anything I'm typing equate or help? I don't know... but I think the best answer is to reach out to Eibach. They take customer service pretty seriously, and when I thought I'd only get an email back, they actually called me to talk it through. My setup is similar to yours, but I do have different components.

I had the same exact set up - the lift dropped almost an inch.
When I called Eibach to ask them about it, they told me they had no clue how a bumper and winch would affect the suspension.
It was clear they hadn't actually tested their suspension offering IRL.

Thank you for taking the time to respond. While different parts can have different weights, it would only make sense to me that there would be some sag associated with adding 150 lbs to the front end. I'll probably give Eibach a call to see what they have to say.

Thank you for the response also. I called and spoke with someone in customer service. He said the front springs should support the weight of the new bumper and winch. Respectfully, based on the few posts I've read, including yours, I'm thinking there will be a little drop. I'll have to consider a new set of front springs as that will likely be the most affordable option. Thanks again.

You should be running a 650 lb spring rate with that combo. The stage 1 Eibachs are probably 550lbs and will sag about an inch with your bumper/winch combo.