The simple answer is - try them. It won't cost anything to try and is likely to work fine.

Grab about twenty pounds of wheel weights, melt them down (themetal clips and dirt will float to the top of the pot),clean the crud off (I use a large aluminum spoon to scrape and scoop off the dross- works great), flux it the way Cayugad said, cast a bunch of balls, and see how they shoot for you with a good tight patch. Who cares about expansion with a .58.