Motor rebuilt & it won't idle for very long???

HI guys hope you can help me out. I just had my 98 cobra motor rebuilt and it won't stay idling for longer than 2 minutes. I had a bad IAC motor and I replaced it. I had ran it with open headers and everything seemed fine except a ruff idle. Here are the details of the motor. I put in stage 2 cams and a complete recipricating assy. from Sean Hyland. I know the computer has to relearn everything but I can not keep it running long enough. It started out idling ruogh with the open headers, then I hooked up the exhaust and it would not idle at all. So I then installed the new IAC and still no idle, then yesterday I figured I would run it around the block hoping to relearn the computer. Didn't work, so I was fed up and tired of racking my brain. so I left it alone and went back to the garage this morning and started screwing around w/ it again and it will idle on it's own but now for only 2 minutes. Any one have any suggestions???? I can really use any help, it's killin me it 90* and beautiful where I live and I am stuck rollinng around in my hooptie winter vehicle.

Thanks man, but I don't know if that will help when it does idle it surges. But I will try it and see if it works. I just had my engine builder over this morning and he thinks it might be my MAF it is at 27Hz does anyone know what it is supposed to be reading I live in cleveland OH, he thinks it is supposed to be up in the 148- 150 range he is going to double check. Other than that the only thing I can think to do is have the computer programed back to stock so that it can relearn itself.

Are they located in Cleveland? I will check out there web site and give them a call thanks for your help. I had my motor guy over this morning but he has not gotten back to me yet. He is a typical engine builder hurry up and wait I took my motor to him in january and just got it back last week so any research I can do myself will get her back on the road a lot sooner. Do you go tgo any shows around town? If so Solon is having an all Ford night tomorrow maybe I will see you up there. Obviously I won't have my car there but maybe I will sneak my chevelle in.