The 3.0 wasn't bad after fixing the valve guides, t-belt, etc. The 604 could be fixed(we had a local guy that had those down pat). I could have a 604 on the floor in about 30 min and pulling those 3.0 heads we did blind folded(shop I was at did LOTS of both!!) Evap cores....not so much. Ugly job! We did them..... but usually put myself and the boss on them just to get them out the door. Typically about an 8 hr job.....we knocked them out in about 4. Shop made lots of $$$$ fixing those minivans!