W123: Noise after replacing valve nuts

1985 300CD-T.

Prior to acquring the vehicle, someone adjusting the valves used too much force on the adjusting nut at each valve. This resulted in the nut sides being damaged and made it very difficult to fit a wrench around the nuts.

Recently, I replaced all 10 of the cap nuts and adjusting nuts and set the valves to factory manual specs. The result has been that when first starting the engine after letting it sit for 14 hrs. or so, there is a noticeable clacking for around 5-7 seconds that then goes away. I have since rechecked the valve clearances and they are all within spec. Does anyone know if the addition of new cap nuts would cause this abnormal clacking for a while? It just seems that the valves are noisier than they used to be

I'd appreciate any advice on this. Thanks