Upper fork caps stuck

First off, I'm new here. so..."Hi everyone"! I have a 79' 650sr with 8000 original miles. Bike is in great shape overall. The problem I'm having is the fork caps. They are the 1/2" drive square caps. I loosened the upper triple tree and had a 3' 1/2" drive ratchet on them. They did not budge! I put considerable force on them and they almost act frozen. Any ideas here? Any of you run into this same problem? I'm guessing they have never been removed. No marks on them and the fork seals leak.

I use a air impact wrench. Roy

Ive had that same issue with screw in frost plugs/galley plugs on cast iron engine blocks before,sometimes this trick works.
remove top triple tree,then heat up the area of the tube directly around the plug with a propane torch.
while youre heating the tube/cap take a wax candle and rub it around the area where cap threads into fork tube,let the heated tube melt the wax till it runs in around the threads.
then try breaking the cap loose

Could also try applying dry ice directly to the cap immediately before attempting to remove it.

Good Fortune!

I would soak them with Kroil for a couple days, make sure the upper pinch bolts are loose, and give it another try. I'm not trying to sound like a salesman, but Kroil really does an amazing job freeing up frozen fasteners. Ed

do you have the front wheel off ground?
you got to take weight off springs first or YOU will get a face full of spring and oil not good!!