[Bob Bidonde]

The hole was in the casting pattern, and not bashed-in. Having taken apart many engines, the hole in question is rarely nice and round. More often it is irregular.

The concern with an irregular hole in the block casting is that the bottom of it is about level with the top of the nearby lifter bore. If the hole extends too low, it lowers the oil level in the valve chamber, so I paste a piece of sheet metal with a round hole in it to the front wall of the valve chamber. JB Weld works well for this fix.