What is the end goal here on a 25 year old sled? There really are no negatives to the airbox. The S chassis airbox's are one of the easiest ones there is to R&R. Why would you want to suck hot under hood air into the motor?

 

filters that hook up to the outlet of the carburetor.

I've never seen filters between the carb and the motor. If you're talking about the pod filters that mount to the carb intake, I agree with 700 above.
That said K&N make filters like that. Checkem' out.

 

Yeah. Why?
Want to lose performance?

 

If you use filters instead of the airbox you are opening a can of warms, you will need to re-jet your carbs.

 

Apparently the powers on here think you should refrain. HaHa

 

The only upside is bling under the hood if that's what you're into.

 

We were all young once. I did it back in the day, and we both survived!

 

you'll have to jump up the jetting too with no gain in performance. The Doo airbox is best......

 

Gutting the air box and rejet is an instant 200rpm. Did this to all my 670’s. Other guys I know would do the same with the same results. I’ve never done the pod filters as I always thought they’d just suck warm air.

 

I think most guys tried these changes. They worked well back in the day. But likely won't work today. A lot more experts today! The warm air story is very true if your sitting idling. Most often your going across the the lake, or trail when its -20, at wide open throttle..