on a street car, ram air doesnt actually add much horsepower
the cold air, that goes through a scoop, now thats a different story
and cowl is less likely to get water and will feed probably more cold air under your hood
get a K&N filter (more resistant to water; recommended for boats), use a regular/chrome lid to cover the top and try to cut the whole straight over or slightly behind the filter
i plan to enlarge the hole this weekend;
mainly because i just put a spacer under my aircleaner (last sunday) because it wasnt sitting properly (the drop base was hitting the eletric choke mechanism - so it might have been letting dirty air come underneath one side)
*and also because i have much more room to add cold air

so now with my torker 289 intake, carb spacer, and breather spacer; i have absolutely NO room under my hood (this is another reason)
i had it like that for 2 years (no breather spacer)
*i bought a completly new (used) hood to cut a whole in, my original is in the my dads shop - hence the different color paint... the sun is very problematic
hell, you dont even want to see the peeling on my roof and trunk
yes i have a big arse oil leak from my intake above 3000 rpms or so
my parents 73 mach one has the holes in the naca hood...
and there are no problems from water, the holes are not even near the carbeurator -- unless your wanting a ram air setup