Can you recycle, say, a cast iron head? How much would they give you per pound? What about aluminum?
Ya catalytic converters will bring in some good coin! In western washington there starting to have some problems with drug adicts stealing the cats from parked cars! they just crawl under there and hack saw them out. would you be shocked if you started up your dd in the morning to the suprise of it being open header!

Can you recycle, say, a cast iron head? How much would they give you per pound? What about aluminum?

i work at an alum fab shop making oil pans and valve covers and there used to be a huge trailer FULL of aluminum, old mess ups and scrap metal. it was like 8 years worth of stuff piled up in the trailer and we took it down to the scrap yard one weekend. turned out the trailer had like 2.5 tons of aluminum and my boss got like 3000$ i think alum around here is 60 cents a pound. it was ALOT of metal and it took rakes and elbow grease to unload it all. sucked for the scrapyard, they have a huge magnet on a crane to move stuff around but for our load it was useless, so it was even harder for them to load it back up hehe.
check out propan.net
its some good stuff