Does anybody know what might cause an eco to have NO compression in cylinders 2 and 4?

Timing seems to be on, and no coolant in the oil. I could see cylinder 1 and 2, or 2 and 3 if i blew a head gasket, but this motor just went in. We just finished building it. I'm wondering if there could be a problem with the machining on the head.

I guess the next step is to pull the head off..... I'm just trying to avoid it. 1 and 3 reach 175 pounds of compression, 2 and 4 don't even make the needle on the compression tester bounce.

Thanks for the input in advance....