You should always check your derailleur stops when changing freewheels, especially with different brands.

It should be pretty easy to do, just put the bike up on the stand and make sure you can shift into all gears, don't over-shift into spokes, or off the high end. And, the chain goes straight into the derailleur.

If you have a B-Screw adjustment, you can make sure the derailleur is as close to the freewheel as practical without touching.