I put a magnet in almost ever rear end that I build. I have a magnetic plug in the rear end in my Camaro. It's always a good idea to try to trap as much metal as possible.
I ran a rear end business for 15 years, but I closed it back in June. Too much to do and not enough time. I'm also a toolmaker for GE aircraft engines. Trying to work 2 jobs is more that I want to do these days. I learned a lot from the rear end business and I don't want to waste that information just because I'm not doing it all the time now.