Hi Jordan,
I had been running in to the same issue few days ago as I was to struggling to get the pulley off. The 1mm movement was the same on mine but the pulley would not come off no matter what I tried bought 3 different pullers too but no luck (I did not want to use the heat method at all) it’s just the pulley that’s tight.
I was going to do a separate write up on the forum regards to this as it’s just an another method which I found easy.
So I basically did this on the bench but it can be done in situ but the radiator will have to be removed.
I came across this inexpensive puller on Amazon which did the trick with no hassle but you have to hold the puller in the Vice while you tighten the center bolt and it will pop right off. These damn pulleys are tight.
Also when the puller is held in the vice make sure you have a helper holding the steering pump as the pulley will come off with pressure and the pump could fall.
See the link below for the puller. It’s on UK site but I am sure it’s available every where.
Also see photo of my pump with woodruff key (ignore the white stuff on the pump as that’s just a rust preventative)
This tool fits really snug over the front end of the pulley and it holds it well.
Zoomtools Bearing Puller tools Set, 5 Ton Capacity Bearing Separator, Pinion Wheel Bearing Removal tools Kit with 2" and 3" Jaws, Wheel Hub Axle Puller tools Set, Heavy Duty Bearing Splitter Tool Kit
https://amzn.eu/d/8MnNIXD