Cylinder head/cracker problem

Hi guys! I’m new here in the forum and I’ve already read a lot about the Krummer problem of the Omega B. But it’s even more complicated with me! It came to me 5 months ago. The old (first) Krummer was found to be “tore” (135tkm), trouser tube leaks. Both were exchanged in a free workshop. Since then I’ve already had the 4th (!) Krummer in my Omega. The first one lasted at least a few weeks (approx. 3000Km), the next one then almost only days. It was always the case that the box sounded bad at cold start, and then there was nothing more to be heard in the warm state. However, according to the workshop, the cracker was always warped. At the last change before 2500Km it was said that some threads were being drilled up now. Well, I thought, the main thing is to help. And now I hear in the cold start in the morning. d again the valves chirping! Can one tell me if the boys have systematically screwed up the cylinder head or if there is another explanation for it. Does the exchange of the trouser tube at the same time perhaps influence (voltages?). Since I am very attached to my station wagon, it bothers me that this problem is not to be managed. However, it doesn’t get any better. Whether the Opel workshop can still help, or if then another head has to be on it??? I don’t have any More plan, please say your opinion.