I don't remember the exact rate, but cast aluminum, that has steel studs and stuff in it is called irony aluminum, and at least around here, it fetches a good rate. It has been awhile since I called for the rates, but I think it was like 75 cents a pound last time we sold that stuff. We have sold off many small car trannies, and cylinder heads.I scrap them only when beyond any hope of re-use. And then you have to strip them down. Most metal guys won't give you much for them if they're "mixed" metal. That means all studs, bolts, etc. are removed....
- Scott