what main bearings do you use in a slant 6

On my last /6 build I used TRW bearings I found on eBay
I saw a set of those. I went back and bought another set of the Michigan bearings now that I know why they had 3 different numbers on the box. I never had a problem with the fit of them but was kinda skeptical since I paid attention to it.I believe that the TRW bearings I looked at had the same issue. It had a MB1999, MB 2000 and a MB2001. Thanks