Clunking from rear end

Roadrat

My first post, although I've been using this forum as a resource for a couple of years, so thanks guys. Anyway I bought a 2010 GT manual a couple of years ago, it was the cheapest car on Ebay spur of the moment purchase so I guess I deserve it, but it's been a bitch to get sorted, although kept me busy during lockdown. It was a partially repaired CAT D write off, had been slid sideways into a curb and smashed the wheel, but because it was rusty as hell underneath, nothing would unbolt, somebody had tried with heat and failed. An induction heater tool did the job for me though, I reckon it saved the car,
I only sheared two bolts in the end dismantling the entire rear end, but it took days.

So to cut a long story short, after replacing all the bushing in the subframe(solid), diff(Polyurethane) and suspension(standard), sandblasting and paint, new hubs, W brace, disks, one spring bucked was compressed in the accident and a bent tie bar replaced and it finally came up good on geometry set up. But it clunks when pulling away or stopping on rough surfaces or hills, standard thing with rear wheel drive cars some people say, but it's annoying. The kawasaki castle nuts and Honda grease mod is done and I've changed the drive shafts with some low mileage ones that turned up, but no difference. I'm starting to think diff and I've sourced a spare but lots I've read says it won't make a difference.

Sorry for the long post, but I guess I'm just trying to sound out where to look next or should I just live with it.