I just rebuilt my top end. Has 50,000 miles. My cam bearings were within spec so I'm running with the original ones. If I ever need new ones I will make my own with Nickel Aluminum Bronze. Same as my new valve guides 😊❤
I'm not a specialist. But those journal bearings looks completely crap. They seems to be made completely from steel. Normally there's 2 or 3 layers of different metals.