Hi ammdc7 (name or part no?)
1. I am no expert but from first principles.
2. What did you do with the head to check there were no cracks and that it was true and flat - while it was off?
3. If you are confident true and flat, and that you have assembled correctly etc. Then:
4. Before you go slitting your wrists I would give the coolant system a thorough flush maybe with a bit of detergent introduced to scour remnants of oil from the cooling passages. Oil in cooling passages is bad news and can lead to local overheating and cracking!
5. I could not recommend what sort of detergent/doseage - but an expert will surely be along shortly.
6. I would get the engine up to op temp with detergent and run for say 10 mins or so before dropping the charge out and then conducting a good reverse flush ( maybe even take out stat during later flush procedure).
7. The reason I suggest this - that is possible oil got into coolant circuit during the maintenance procedure - you may be the best judge of that - of course. Anyways eliminate this first. If oil comes back after this then you have a problem and maybe the head is going to have to come right off again!
Best of luck!
Edit 1: I have just given an answer to a question you did not ask. Coolant in the oil - only my paras 1, 2 & 3 apply!