This is exactly what I had to do when I moved to 37s. Even after adjusting caster and everything new under the front end, it needed a touch more toe-in to be happy going down the highway. Wouldn't notice around town at all. Check all other things first obviously so you aren't covering up a real issue, but a real alignment sheet will tell the taleThat a very complete kit.
With the new 37s you could need more toe in.
If you have someone that can help you, have them move the steering wheel back and forth while you look at steering components ( tie rod ends ) for excessive play.