sounds like your block is a 2.4 liter and those heads were known to cause over heating. If i remember correctly from when I was building my engine for my hydro stream going to a 1 piece head was a common upgrade for the engines. I might be completely wrong because I am going off of memory.
I found an old thread at scream and fly.
http://www.screamandfly.com/archive/.../t-222987.html
Looks like you are good to go, don't go with the 2.0 liter heads stay with the 2.5's because of the compression.