I was installing the 2 gen. bracket bolts that go into the eng. block and they were going in hard.  They are 5/16-18.  They look gauled but I'm sure they are 5/16-18.  Anyway i'll replace them just to be sure.  My question is when I stuck an awl into both holes to measure the bolt length, the upper hole has a solid hard bottom to it but the lower hole was soft so I pushed the awl in and antifreeze water came pouring out .  Is this normal that the lower bolt goes into the water jacket and the upper one does not or did I punch through some rust?  The water was clean and rust free.  Any thoughts?
Thanks, Charlie 

Charlie,

It's open to the water jacket; use sealer on bolts when installing. This also goes for some of the water pump bolts on both sides.

Regards, JLB

55 Ford Crown Victoria Steel Top

Charlie, yes that lower bolt hole is open to the water jacket.  Put a little gasket sealer on the threads when you install it.

John - "The Hoosier Hurricane"