Weird, I added a comment here the other day, but it disappeared...

The correct spelling is Bel-Ray.  This can be seen on the street signs, which is the canonical source for naming.  It's also spelled that way in the govt GIS sources.

Is it spelled differently somewhere else?  I spot checked a few things nearby, but they all appeared to be spelled correctly.

Fun fact - Bel-Ray is short for Belton-Raymore, the two cities that share a bounday just a few meters east of the southern intersection of this blvd and 171st st!