We've owned it since '03, could the previous owner have used that much stop leak without us knowing about it before now? Also, the mechanic at the dealer we bought it from is my brother in law and I do trust him. We checked for cracked head when it first overheated and it wasn't cracked. The temp is running the same as it did before we ever had problems. Although it does take longer to get to that point than it did before the problems.
I'll have them check for a vacuum leak, we've had that problem in the past so maybe it wasn't completely resolved.
Thanks.