Relative resistance of the wiper linkage

Guys,
I'm in the process of connecting the wiper linkage on my son's '74 Duster (it's been disconnected for years by the previous owner), and I went ahead and replaced all of the plastic clip bushings. I hooked it all together, and I noticed that the linkage was really hard to move....I'm a big guy (6 ft @ 250 lbs), but it almost takes two hands for me to move the wipers back and forth.

I figured that was normal, so I connected the motor and hotwired it under the hood to check operation...and the damn thing will hardly move! The motor and wires get hot, and the arms move slightly, but that's it. I thought the motor might be weak, so I took it back off and tried the power...it spins like a top, and seems to be rather fast.

This leads to the question of, how powerful should the motor be? I can hold the linkage tab with vicegrips and when I apply power, I can actually stop the motor from turning...is this normal?

The other question was about the linkage as a whole...shouldn't it be really easy to move? Not floppy, per se, but smooth? Here are the wiper pivots and seals:





Those babies are grungy, and REALLY stiff to move...is that normal?

If not, is there anything I can do to them, or soak them in, to loosen them up? I'm not in the position to buy new ones right now, so I'd like to fix these, if possible....any ideas?

Thanks,
Rob