where do I get pitman arm nut?

Finishing up my power steering conversion. I thought it'd bolt right in. I wanted it to take 5 hours, should of known better. The new ujoint caps were too big for my yoke for the column, so I welded a file to a sawzall blade. Quick work. Radiator has to be remounted an inch or two higher. couldn't get the new boot on the column. gotta cut the bottom of my grill. Had to repair the super long hoses with compression fittings (pump is mounted on passenger side). The custom hydraulic hose manufacturers couldn't make them. Finally, can't find my pitman arm nut. I got a ford nut but its a coarser thread. Where can I get one? Flaps? mail order? hardware store? I'm gonna finish up tomorrow. hopefully.

 

Hardware store or junk yard... Speaking of which I need to replace mine too.

 

The last one I got was at a local Hardware store. They had the exact one in grade 8.

 

Did you try your local auto parts store? My local Auto Value and Napa stores have many drawers full of auto specialty hardware.

 

Anyone know what size it might be?