How are the intake bolts in the lifter valley....they go into the head unless the oil that goes through the head to the rockers has the intake bolts protruding into that it's the only place I can see oil traveling up the bolts.
They don't actually go in the valley, but I know what he means, the intake holes are not blind in the head and they go into the area of the head that the pushrods pass thru. The theory is that being the bottom of the holes/threads are exposed to oil it can wick up the bolt and end up pooling in the intake. I myself have not had this problem but just because it hasn't happened to me it doesn't mean that it hasn't happened to someone else.
The only thing that I would offer on sealing the threads is that I would not use teflon tape. Some may end up in the engine and plug something. Best to use some sort of liquid sealer.