AMC? heads

[JIMP]

Hello all,
I just found somewhere in my country, new T4 1800 heads. They are complete with valve guides and seats, less the valves. I looked on them to see what casting are they and the only sign on them is the word AMC casted on them. Do you know what this means and if they are any good for making from them some serious performance heads? Their price was fairly good (I think), something like 110Euro a piece (don;t forget they are unused). So, what do you think?

JIMP