if the valve has 4 holes (and 4 connecting "posts")...I'd just file two opposing posts out and make it all neat and tidy.
If it had 3 holes...I'd probably try to remove the stem and drill/mill them out a bit bigger...but honestly, it'd be easier to just buy a hiflow. (I'd still do it...but would save it for a boring weekend when I want to get out of work around the house
)