Huck,
There are commercial broadhead alignment checkers available, but you can make your own with a board and four bullet-shaped field points. I don't remember what bit size I used to pre-drill the pilot holes for the field points, but somebody will chime in with that info. What your looking for is being able to screw or glue 2 field points in side by side about 12-18 inches apart. The head shoulders serve as bearings that you can lay the arrow across and keep it level and wobble-free while you rotate it. You can mount another small board or reference plate at one end to place the tip of the broadhead against, to look for tip wobble. I usually check WW's alignment before I trim the tips because it's easier with the needle point intact. With these heads and glue-in inserts I often find that a tiny circle is the best I can get, as opposed to spinning perfectly true. I usually can't tell any adverse affect on arow flight, but shoot 'em to make sure. You might want to consider epoxy. I've lost heads in tight backstops with hot melt and you can usually still remove epoxied heads by heating with an alcohol burner.