Where should I look to find the casting # on a 93-97 Mopar magnum head ?

I've recently purchased a 2001 Dodge Ram 1500 Magnum only to find out that the motor is from 1993 to 1997. I haven't found the serial number to find the exact year but the engine casting makes it a 93-97, 5.9 magnum. I'd like to know if it has the right heads for that motor. I know the casting # that belong on those heads but don't know where they should be located.|||Pull the valve covers,casting information is in valve valley on top.|||its in the same place its been for years on engine heads in the top under the valve cover,it will have the casting number of the heads,plus a time and date stamp to tell you when they was manufactured,good luck with it.