Heater blower fan cage rubbing

[4thgencreamsicle]

I tried putting all the important key words in the title. I also posted this in an “All about heaters” thread for a bit earlier truck because there didn’t seem to be one that spanned the 69 era. Anyway here is my issue, copy/pasted from that thread:

So I got the cage from Brothers and the blower motor from LMC. If I put this together the way it’s SUPPOSED to go, with this little square dude on the shaft first, then the cage, the cage blades rub the box all the way around when installed...bad. But if I remove this, it would fit perfect, I’d just need some washers to take up space on the shaft. How important it that square spacer? Seems like it would keep the plastic from getting worn at the base.

Or do you trim the cage blades? If so, with what? (Leaning towards this one, but not sure an exact o knife is the smartest choice since it’s kinda hard plastic, I’m kinda clumsy, and fingers are important)

Or do I buy a new cage from LMC and they magically match up because they were supposed to be bought together all along?

Help a girl out.