So, I just installed a K&N lunchbox filter and rejetted the carbs on my bike.  After putting everything back together, she runs great!  She really pulls and the lunchbox added some sizable low-end growl to the exhaust note.  However, the bike reeks of gas, and I mean it reeks.  I haven't been able to spot any fuel leaks, but I'm getting a fair amount of oil coming out of the crankcase breather.  The oil does smell of gas, but the fumes are so potent that I have to assume there's an actual fuel issue.  When I had the carbs apart, I set both floats at the proper 13mm +/- 1mm float height, and I also inspected the needle valves, which looked fine.  I did not remove the needle valve seats, which may be a mistake on my part.  Is anyone familiar with this situation?  Like I said, the bike runs great, and I can't find any leaks, but it definitely smells.  The exhaust gases smell of unburnt gasoline, but I'm not getting any soot or black smoke.

Note:  All of the valves are tight, as in out of spec tight.  I'm waiting for some shims to show up.  I don't know if this would have anything to do with it, but there was no gas smell before the filter install/rejet.

Some thoughts:

Does oil smell strong of gas from dipstick?  If so, change oil now and fix issue before engine damage.
Get a filter for the breather. Look on wiki for the model number
Are you running real rich?  Sounds like a possibility.

Tge last time I had strong gas smell one cylinder quit firing. Do you have good spark?

It seems the smell is definitely oil in the gas coming from the crankcase breather.  I don't know why I never thought to check, but I took a whiff of the old airbox and it reeks of gas as well.  I'm guessing I never smelled anything before because the vapors were getting sucked back into the engine.  The float levels are pretty close to where they need to be according to the clear tube method, and the bike runs great, so I'm assuming the PO flooded the thing at some point.  I'll be ordering a new oil filter first thing in the morning so I can swap out the oil.  I'll definitely put an inline filter on that breather.  Hopefully this will solve my problem.