I don't like to use sealer on studs or bolts, I think it is best to have clean threads on the bolt and in the block then use a little assembly lube or just plain oil. On blocks that the threads go into the cooling jackets (scrubs) I use a little block sealer (we have cubes that I put into the water jackets before installing the expansion plugs) and always start a fresh engine with water, no coolant untill everything is ran-in and adjusted and ready for the road. If you get a little seapage it usally stops after a few minutes running.

Tim, why do you use water on initial startup?

I use water for a couple of reasons; first of all some gasket manufacturers recommend it because glycol is too slick and head gaskets might not seat correctly. Second is for the simple reason you might have to brake open the cooling system for some reason and waste the antifreeze.

Also I wanted to add to my first post that when using oil on the threads of  "blind" head bolt holes, like the Y, a thin coat is enough. Too much and you can hydrolic the bolt and get an incorrect torque reading. A little sealer on the manifold bolts and studs is OK I understand some guys have had trouble with leaks in this location.

It seems to me that for the initial 20 minutes of cam breakin, an objective would be to get the motor up to temp soon to facilitate the oil movement into the cam lobe area.