This came up in another thread, but thought it deserved a wider audience, as it applies to much more than the scope of that thread. This is a comprehensive post about break in. Ring seal is BIG. Lake Speed from Total Seal is an oil specialist and piston ring guy. Excellent resource.
Break In Oils
Lake Speed at Total Seal goes over the in/outs of break in oils. There's more to it than ZDDP. Some additives are NOT good for break in. They do not recommend a specific brand, but let you know what is GOOD for break in, and what is NOT. They also show a link for test results of a bunch of oils commonly used for break in, as well as specific break in oils. VERY good watch.
This is the link to the oil analysis. Below that is a video showing what oil is good and bad for break in, and below that is a video on proper break in procedure.
https://www.speediagnostix.com/s/Bre...il-Report1.pdf
Dos and Don'ts of Break-In (oils, etc)
https://youtu.be/teDgJgPeeeU
Proper break in procedure
https://youtu.be/6XEYJrSqHtw
Driven BR40 Break-In Oil $7.99/qt
https://www.summitracing.com/parts/jgr-03706?rrec=true
Lucas 30W Break in oil $31.99/5 quart jug ($6.40/qt)
https://www.summitracing.com/parts/luc-10631-1