When young and probably foolish I put K&N pods on my 400. Older and maybe wiser now, I suggest you accept the challenge of the airbox and forget about pods.
I am not a believer in the omnipotence of Honda engineers, that the stock intake is perfect and ideal. It is, like all designs, full of compromises to meet many goals and constraints. But it does work nicely.
And yes - your engine with pods will run with no tuning done. It will NOT run well.
The tuning takes time and experimentation. You can use a dyno... but dyno time is expensive and carb tuning is a forgotten art in mainstream performance shops now: they work with laptops adjusting engine computers, not with wrenches and screwdrivers swapping tiny brass carb parts.
You can go old school and tune by repeated adjustments with plug chops, my way. You will become very experienced at carb stack removal and installation, and need to collect a number of sets of somewhat expensive (and now hard to find) jets. You will probably need to change the needle tapers slightly using rather dubious methods.
As often repeated here by those that learned the hard way, Keyster and other brand aftermarket carb brass is not so good. Only genuine branded Keihin brass parts are reliably sized. You can use off brand ones, but be aware that a Keihin 115 and a Keyster 115 rarely if ever give identical results. I stopped using them after my first experience, so I can't say if Keyster jets are consistent, but experience tells me that all Keihin jets I've bought have been good - a 115 bought last year to replace a 40+ year old one lost by the owner gave no trouble and that cylinder ran just like the other three.
The airbox is stupid difficult to remove and install, true. However- you will rarely (if ever) need to do that.
With pods, doing the tuning well enough to achieve the performance and rideability the stock system delivers will have the carbs out many more times than is fun.
