[Rob]

I believe this is one of the few things not completly revised on the IAII blocks.

I'm pretty sure several of the holes are what holds and locates the patterns when the block is poured. They become water holes, I'm pretty sure set up in stock locations. There are a couple of places where a second machining operation made end mill type cuts on one or more of these holes which I believe Bob and Frank already have worked on with Roush(probably the area where Wade had a deck plugging adventure). When the bore becomes siamese and 4.300 plus, o-ringing has always been a creative excercise(I would figure eight the wire ring for the two center cylinders and adjust the outers to stay out of water holes. Regular head gasket fire rings end up on top of stock placed water holes.

Not sure how Bob and Frank plan to offer the deck as many people want dry decks, many want plenty of cooling water holes, and others custom. I proposed a 5/16 hole in the same area of stock locations which is the drill size for 1/4 inch pipe plugs making life easier before decking. They may do much of the plugging and decking operation or leave it up to the individual engine builder. Many of us can handle the deck in any configuration, but if a private individual gets a block for street car type stuff, it would probably be best if they had a easy set of water holes and simple headgasket.

So what this long winded post boils down to is water holes on big bore blocks will need to be smaller for sealing. This will require water hole plugging of the casting before decking and then machining the water holes or not(dry decked).

-Rob