[wingnut60]

I would double-check your clearances, but yes, they don't come any narrower than 22-24 and all of the trailers I have been in are set up for this size, not any larger. A KR may be different, it was a great trailer in its time.
You are going to have to vent the dryer somewhere--wall or floor are the choices, and a hole is necessary. Again, all the trailers I have seen have the vent exiting directly behind the dryer vent line into/thru the wall--this is simple and direct, leaving no bends to collect lint and clog up. Vent kits are available at RV stores. You drill the hole with a hole saw, after doing your darndest to make sure there ain't no wires or studs where you are going to put the hole. Measure 10 times, then once again, before drilling....
There ought to be a KR owners forum somewhere on the net, maybe even on this forum-haven't thought to check. Google for that, may be someone with a pic to help you out.