wat are these heads for, from, and worth?

 

anybody got any info on these things?

 

I googled Chevy head casting number 376450 and came up with them being a 75-81 ...262/267/305.. 6 or 7 exhaust bolt holes, 60cc chamber. I can't find anything that says they're aluminum. Basically they're a small chamber smog head. They can't be worth to much.

Here is one link-

http://www.mortec.com/castnum.htm

Google the casting number and you'll find more of the same.