After replacing a cylinder head gasket I reinstalled the cam timing chains and reinstalled the chain tensioner. The chain tensioner just seemed too tight so I removed it and reinstalled it a few times trying to figure out what I was doing wrong??

Finally I thought it was okay but obviously it wasn't because now I have a broken cam.

Where did I go wrong???

The chain guides have a little wear but should I replace them?

MB told me the cylinder head torque was 40 lbs plus 90 degrees two times, that seems like a lot to me?

Thank you for any help!!!!
Chris