I don't know how to tell a 1/2 water head. If it has all the normal water passages that would be good. If not I wouldn't try to use them. I have one now that I use for a mock up but I would like to have a pair. Mine appears to have normal water jackets. 1/2" head bolts and o-rings for top fuel. They might all have the same casting number. Mine is P4120711. If you can text me photos that would be great.

2011 Drag Pak Challenger