Ok, I did some "quick" (not so much) research on the IN DNR site and reviewed the jaw spreads on a couple traps. Looks like you're good to setting up to 220s on dry land (depending on the trap manufacturer (some make their traps slightly different)).
TAKE NOTE: Dogs CAN get their head in a 160! If a dog sticks it's head in a conibear, it's DEAD. Plain and simple. So if you're in an area where guys are running coon hounds or bird dogs a lot, you're kind of asking for trouble. Even dogs as big as a lab. My friend didn't believe me so I took a 160 (not set of course) and called my lab Syrus over (who's about 90 lbs) and easily slid the conibear over his head and all the way onto his neck.
Moving on, since you CAN set on land, that opens up the possibility of catching foxes (and MAYBE a dumb, retarded, blind, and probably deaf (for good measure) coyote). You need to study 2 sets. Cubby sets and blind trail sets. These are going to be your bread and butter for coons primarily but will pick up anything using the trails, particularly with the blind trail sets.
Red O'Hearn is from Indiana (I think) and that guy puts up HUGE coon numbers and catches a good number of fox all in blind trail sets.
Start reading and learn how to disguise the traps on the trails, an animal isn't going to just walk through a hunk of metal set up on a trail, you have to blend it in and that's easier said than done.
"Knowing when to shoot and when to wait is one sign of maturity in a bowhunter. Be patient and pick your aim point carefully." ~ Randy Ulmer
"I suppose it's the way of hunters. We are very odd fellows." ~ Peter Hathaway Capstick