www.car-parts.com has two listed, one off an 87 603 and one off of a 94 603. The 87, they want $1,000.00. You have to call for the other one or two listed. There is a place in Columbus, MS (Cylinder Head Exchange or something similar) that advertise if you call them that they can fix that head for about $300.00 if all they have to do is fix the crack and finish out the valve job and resurfacing the face. The valve seals are extra, I think. A while back, you had a good selection of choices to find a head at the car-parts.com site, but for some reason, the heads have dried up.

BenzDiesel