440 oiling mod question

I have drilled the #2,3,4,5 main oil passages out to 9/32" like the tech archives say to do. My question is why shouldn't the #1 main be drilled? Or should it be? Thanks guys!

I don't think the #1 main oil feed needs to be larger since it is fed directly from the main passage from the pump leading to the lifter gallies. The #1 main is the first exit for the oil system.
That said, it's not a problem if it's opened, the correct bearing clearance will maintain the needed volume for the remaining exits.

Just curious, how did you drill it? Did you use a ream or a drill bit? Hand drill?

Thanks

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Just curious, how did you drill it? Did you use a ream or a drill bit? Hand drill?

Thanks

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I have used both a drill bit and a reamer with a pistol drill.

I have drilled the #1 also ...