fresh rebuild start up problem

Only way to know forsure without pulling it apart is to just fix the issue and break it in like normal and see how it does. I bet your ok tho. You haven't started to develop a wear pattern on the cam/lifters if it hasn't run. So just make sure when it DOES start it has good pressure and you keep the revs up 2000-2500 for 25min and vary the speed every so often and make sure your cooling system is functioning!