Inliners International Forums General Discussion Engines 250 block question - dipsticks

This motor is going into a 1963 Nova. I know I need to use the hole by the distributor for the dipstick with my stock 194 pan. My question is, all three of the holes circled go all the way through the block. Do I just need to tap and plug the middle and back holes? Any idea why there are three holes that were drilled all the way through? This was a running motor at one point before the guy pulled it for a V8 but I don't see any evidence of plugs or anything. Thanks guys, I appreciate it.

Someone may have re-drilled the block. The rear does look like it was the stock hole. But yes you can tap and pipe plug them.