looking to upgrade my teraflex 2.5" budget boost to a true coil spring lift kit. In addition to the current budget boost, I have a 1.25" body lift. The plan is to have enough lift for a 37" or 38" tire after the axles get lockers and 5.13 gears ect.

Currently im looking at the rock krawler 3.5" X-factor lift, cant really decide on the shocks for this lift......options I'm considering are

bilstein 5100
fox evolution or (possibly performance) series
rock krawler sport Tuned 2.0 RRD Spec'd Prodigy Shocks

looking for opinions and advice, also any other thoughts on a similar priced lift kit ($2500) are welcome.

 

You can just replace your factor springs and TF spacers with RK 3.5" springs. All the TF brackets work just fine. That's all I did and it's been 8 years. Since I have also added the TF front monster Trackbar, and draglink flip. It's all good in my world.
I run 37x12.50x17 Pitbulls with Bushwacker Flat fenders.

 

OP has the TF budget boost....there's not a whole lot that will be left once those pucks come off. If putting on a quality 3.5" spring, those sway links and everything else will be too short. Better off pulling that stuff off and selling it as a package to next person in need of BB I'd think.

In regards to shocks, I can't speak for the RK's, but I don't think you're going to notice a big difference between the Blisteins and the Fox shocks performance wise, and they are pretty close in price. Unless I'm mistaken, the "evolution" series has been replaced by the "adventure" series. Basically the same shock......with the "performance" series being comparable but rebuildable. If you go with either the Blistein or the Fox, I'd focus on lengths since the ride will be similarly stiff. I was after a longer shock and went with the Fox evolutions for a 4-6" lift rather than the Blisteins for 3.5-5" lift. Both the shock body and the travel turned out to be a little on the long side for my build at the time.....whereas the Blisteins were perfect on buddy's similar build.

Dirtman's sticky on shocks/lifts is really good info. He's always pushing for appropriately sized shocks and couldn't agree more.

In regards to lifts, if you're going to do it, go ahead and do it right with quality parts. RK, Metalcloak, Evo, or various others....stick with reputable name brands. Doing a quality lift and addressing everything that you really need to, and adding 37s isn't going to be cheap. If you try to do it on the cheap you'll likely not be happy, so just keep that in mind. Besides the lift, plan on upgrading DL and TR as well (you already have RK TB it looks like), and plan on some decent ball joints and at least a front drive shaft. I'd also replace brake lines rather than using brackets.....some kits include, some don't.

Also.....when doing a 3.5" lift with full adjustable arms, there are things you're going to encounter. The rear axle will move back a bit.....which will cause interference with rear sway links. That solution is to move the rear sway bar back and inch….but then that causes interference with the exhaust. Also, your rear coils will now have a nice banana bend in em….so you’ll either need to use a correction wedge to help, or address the spring perch itself. Coil retainers may or may not be included in a kit, so might factor those in.

Make sure you cycle the suspension properly and verify you’re running proper bump stops. Just because a kit includes certain bump stops doesn’t necessarily mean they are the correct size as different shocks and tire sizes will influence those requirements.

As you can see.....there's a lot to think about besides just shocks if you're going to head down the path it looks like you're trying to. I highlight these sort of things so you can be realistic about costs.....there's a lot more than just the cost of the lift and shocks, and all that crap adds up.

Back to your original question, the Blisteins are pretty decent value for the cost.....as long as you realize that a nitrogen shock is gonna be pretty stiff.....not clear if you're still on factory shocks currently as comparison. I've been generally ok with the Fox evolutions ride wise, but wouldn't buy these again due to length.....and the shorter version is too short for me.

Happy building!