My 99 that was built either April or May doesn't have the coil packs. I can't find the casting number on the head but I'm pretty sure it isn't 0331

 

If its got coil packs and is on a cherokee or grand cherokee before mid 02 then it is a 0331 head...

0331 is stamped under the valve cover... If its the revised head from 02 1/2 to 04 grands there is a added stamp of some letters between 3 and 4 cylinders so there is added metal and wont crack...