I suggest you make a proper introduction so that you don't get flamed. Then, move this question to the main board with more specifics about what you have tried and whether or not engine leaked water before or after running. Best of luck!
I will try to help you. first make sure you have 400 head gaskets. Their is a difference. Second 400 heads are very prone to cracking. have them checked. Third the head or block surfaces could not be straight. fourth the head bolts could be bottoming out. this will cause a false torque reading.did you use a tap to clean up the threads. Now that several of the HAMB family has given you advice. Go to the intro section. read about 50 of them then you will have a ider of what to tell us.. You are not the first one to do this and will not be the last. The nice folks here like to know who they are conversing with..Good Luck.. I buy every 400 engine that I find for sale.