I recently changed my heater core and everything seems to be back like it should and working besides when I turn the floor setting on it just comes out of the defrost but the defrost and the normal vents work just fine. I'm hoping it's something easy like a vacuum line and not something I have to take the dash apart again to fix.

 

Perhaps the vacuum line came off the servo. When you switch the the floor vent, if the vac line is off/broken, you'll lose vacuum and it will default to defrost. Have a look underneath.

 

Is there a way to check this without removing the dash?

 

Yep, put your head under the dash on the driver's side of the gear shift. You should see them there.