As best I can tell the engines from 62 - 63 on would have the head mods so it could be used on the aluminum block. There is a good artical at Mopar Muscle about the development of the engines:
http://www.moparmusclemagazine.com/projectbuild/mopp_0303_chrysler_slant_six/viewall.html
I just checked out your aluminum engine! Clean!