My 79 GS1000 has a small airbox with two quarter-size intake holes. On top is a hinged lid, about the size of a dollar bill, for taking out the filter. In the early 80's, Joe Minton, tech guru at Motorcyclist, tested mods on the GS. He took off the hinged lid, added a K&N filter, changed the main jet from a 95 to a 115, and got a noticeable increase in HP.
I took off my lid and got a K&N. I was pleased with the results. Later when I took off the carbs, I added a 105 main jet. The mileage decreased from 45 to 39 and the bike ran like crap. I changed the jets back to 95 and the bike ran great. Joe Minton did his testing at sea level. So it just depends on where you live. But modern airboxes are tested by the manufacturer for flow and sound. I wouldn't mess with them. But I bet your's would run a lot better after cleaning your carbs.