Dull Clunk in front end - need ideas

Hi this is my first post here. Usually im a board lurker. I have a 72 with a james duff 3 1/2 lift and duff extended radius arms and were going through a rough patch in our relationship right now. Ive been getting this dull clunk, its something up front and happens when I go over bumps and potholes. Ive checked just about everything for play, no play in the ball joints (new), spindle bearings seem fine, replaced track bar bushings, c cups are new (though i suspect them a little), replaced the drag link cause of a little play.

Still nothing so I decided it might be the engine mounts - no. So its the tranny mount then - no. Im kinda suspecting the bushings connecting the extended radius arms to the c cup holders, but they seem solid.

I cant recreate the sound in the driveway so im almost to the point of grabbing the front axle laying on a creeper and having someone drive the thing with me under it. Im not there yet though cause that sounds like a quick way to a darwin award. Can anyone help me here, this happen too anyone else?

Make sure the shocks are secure at both ends...caused me grief for a day or two.

I thought about that, took em off to see if it still happened, it did. But I was having fun punching the throttle bouncing the front end. I was kinda over doing it and some black guys in a lowered car on airbags passed me laughing their asses off. lol