Can I plug these oil return holes?

[VTJUNK]

I read somewhere once that on a Ford 302 block the 4 return holes can be plugged that run down the center of the lifter valley. The advantage being that the lifters run in a pool of oil and return oil isnt dripping onto the crank. The oil returns instead down the holes at the corner ends of the valley.

Any opinions on this?

[Scott Liggett]

Most aftermarket blocks do this within the casting. Supposed to be good for a few hp.

[min301]

In roller blocks, these are used for the retaining "spider",
therefore, I see no issue. Non-roller blocks have open holes here,
again, I see no issue.