Pitman Arm removal ??

'73 Duster, Manual Steering box.

The puller I have is too narrow to fit over this Pitman arm, so I've been trying to get it off with my 12 ton shop press. Bathed it in Liquid Wrench for a couple of days, been "tapping" it with a hammer to try to loosen it up, also warmed it up with a heat gun (have stayed away from a torch). Damn thing hasn't budged.

Any thoughts as to why this isn't working?

Thanks.