Please help / antifreeze leak

Thank you for your replies. To answer the questions I did not build the motor, I had it done my a Mopar pro, and he has a very good rep. I don't think its the stud in the exhaust manifold. I really don't want to put any sealer in a freshly built motor.When I got the motor back, all I had to do was put the carb, water pump and so on back on before putting the motor back in. I figured at this point in my life I wanted a professional motor built for my car. The motor sounds and runs awesome, its just this leak that is freaking me out. I went and bought a mirror but it's alittle to large and I can not get back there to see. I know it could only be one of a few things. If I pressure test the motor cold is there any chance of finding this leak? I know what your going to say, why not just take it back to the builder. The thing is he is a couple of hours away and I guess I will have to flat bed the car. I was just trying to see if it was something I could fix, like if it was the intake manifold or a freeze out plug before I would pay to have the car trailered back to the builders shop.