I have always used Dino oil for break in and then switched to synthetic. In the past I used kendall. I have been told their oil is not the same as it used to be. I am not sure if it is true.

Lots of smart and experienced people here. What is your recommendation for oil used to seat rings and break in the cam?

I like the shell Rotella 15W40. Hasn't failed me as of yet.

If you're using hydraulic lifters, the cam manufacturers are reccomending Rotella for break in.

here's the deal, everybody in the car world have lowered the zinc phosphate levels in the oil to help pro long the life of catalytic converters.
Rotella being mainly diesel oil still has higher levels of zinc in it which helps in break in. also go grab a bottle of GM EOS at a GM dealer and put it in.
if your building the motor yourself, the fastest way to seat the rings is to use type F ATF, or Childs & Alberts dry film when putting the pistions in the block. they seat almost as soon as the motors fired.

Thanks Guys!