Im trying to remeber and I tried to look for the thread that was on here not to long ago. With the 2.4 is it the 98 and older head on the 99 plus block that will work or the other way around? I remeber that one combo would work and one wouldnt due to coolant passages. Im slowly collecting parts for my verts engine and I have a ported 97 head with stainless steel valves and all the goodies and a 2001 shortblock.