Im getting a three inch lift (coils in back and spacers and diff drop in front). Since I replaced the stock shocks in the back with procomp 9000 series shocks less than 8 months ago do I need to buy new shocks?
YES! Toss those in the garbage!
ProComp 1.5yrs vs new Bilsteins. The ProComps got beat up and the threads broken off during removal but the shocks themselves were blown within a year. And the Bilseins not only last longer because they're built better but they ride much nicer. Worth the $ every time. I got mine from Toytec along with their Superflex coils.
If you do some research, some say the Billy 5100's in the rear are pretty soft.
Others go with LC struts, either stock or OEM replacements like I have made by Tokico. (both are made by Tokico, a quality Japanese manufacture)
ProComp anything is garbage.
I have zero regrets with the Trekmasters in the rear, and I enjoy the Tundra 5100's in the front. Both are very balanced in terms of ride quality and settings.
Procomps are a cheap shock made for 4wheelparts. Personally I would not run them, especially on a lifted rig. I also would not run the Gabriel or Monroe.
Also the ones that you bought were probably the proper length for a stock height rig. You will need shocks that are longer for the 3" lift.
PS. the front shocks are all the same length (within a small amount), lifted or stock height. This keeps the front wheels from drooping too far and allowing the CVs to pull apart from over-extension.