[Myron Piatek]

I go through several (4-8) heat-cool-heat-cool cycles, not letting it get too warm initially because of the bearing & ring clearances. Running duration depends on radiator efficiency & amount of hard-block. Check everything, put race springs in if breaking in with softer springs, drain oil while still warm, refill with synthetic race oil and go!

As mentioned, magnets and cutting the filter open are always a good idea. I always use a magnetic drain plug for ongoing checks.

Amsoil has a break-in specific oil that works well.