Strut coil questions

About a year ago i replaced my struts and shocks with ranchos rs5000. i reinstalled with the old coils springs and now i am hearing a hollow thud when i run over small bumps. my guess is the coils need to be replaced. Additionally i have an ARB bumper on the front, which adds weight. the OME coils are less than 500lb spring, i am trying to get something higher closer to 600lbs, i found eibach coils on summit and they claim to be universal. im comparing the stock coil lengths/diameter with what eibach and none seem to match up.if someone could help me out i would greatly appreciate it. 04 4x4 4dr tacoma trd

 

The Eibach will add 3" of lift. A standard Moog replacement TRD coil is 590lb compared to non TRD 460lb per Rockauto's website.

 

thanks brother