timing chain slap

[fast240D]

I have a real problem. Just did a double row chain conversion on my 1981 380SL. New everything, Iwis chain, Febi tensioner, rails. gears, etc. Now, in the morning, only on cold start up I get a timing chain tick for 5 seconds to 30 seconds. It never happens on warm start. I replaced the tensioner with a new Genuine MB one. Same thing, no different. I changed dino oil to 10w 30 Mobil 1. No change. What is going on here?