Apex parts causing terrible Clunk on an F350 with full Carli & Redhead

[Motafinga]

I believe that the initial 'clunk' was caused the Carli track rod bar, which we just replaced (1k miles ago) so the original clunk was Carli's, which started with the sloppy-wandering steering about 6-7k miles ago. The steering got so bad that we fitted a Redhead steering box and the full Apex kit about 4k miles ago trying to solve the steering issue, which it didn't.
However, this is when the clunk started getting really bad, so the bad Carli track rod and new Apex overlapped by 3k miles.
On the plus side, replacing the bad Carli track rod bar has totally fixed the bad steering, so honestly the Redhead and Apex were probably not even needed, but we just find the cause of that problem (Carli track rod failure) until I'd driven up to Montana and back.
The 'clunk' has continued and on this trip (so now a total of 4k miles on Apex) and the cluck has became absolutely diabolical.

Sounds frustrating especially after thinking it was sorted. I once had a clunk in my Tacoma after coincidentally replacing a few front end components and it had me chasing my tail since it would happen when the front end would hit any kind of bump. HOWEVER it turned out to NOT be in the front end at all and was a blown out rear leaf spring bushing! Any pressure on the front end would shift the weight to the rear and cause a clunk. It 100% sound like it was coming from the front end though.
I put a set of poly bushes in the leafs and she now rides like butter, easy to do with a jack in the driveway too.
Is your front end coils or leafs?

Just something to think about and check.