I have run a K&N in excess of 200000 miles and have not had a MAF failure yet. It has been proven that the over oiled will cause issues is just an old wivs tale that refuses to die for some folks. GM tried to void warranties but were never able to prove the over oil K&N issue. From the way govt motors has been working I can see why!
Anyhow, if you can get air from pre-radiator to the carb or even better a TBI system then you should see improvement in general but not overwhelming gobs of anything in particular. Sure the oem filters will flow enough, but they too will benefit IF you can get cool non-engine bay air into it.