Chroming Cast Tooling Plate?

I can get inexpensive aluminum cast tooling plate drops at my local metal
store. I like working with this stuff because they're flat enough for my
tolerances that I don't have to face mill all six sides.
I'm going to work up a batch of about thirty parts and want to get them
chromed. I don't know what the alloy is, the guys at the metal shop say the
alloy is "cast aluminum tooling plate". Is there any problems chroming this
stuff or anything I'll need to tell the Chromer?
Thanks,
George