If the clunking started when you put the shocks on the car, it's 99% probably the shocks.
It takes about 20 minutes to change shocks. You can drive the car without the shocks (I mean...don't drive it far though) to see if the shocks are the source of the noise, or you can put your stockers back on.
2002 C5 Z51. MCS 2WNR TT2 coilovers, 18x11 Forgestars, 315's, yada yada. Built Z06 T56. Bolt ons. Coming soon to a CAM event near you.
2013 F150 6.2L. 9mpg.