If you rebuilt "everything" I would *think* that includes the head, correct?
If that is the case, then maybe one of two things has happened, or both.
One possibility is that the cam caps got installed backwards, or on the wrong journal. If you don't know about this it is a really easy thing to overlook.
The caps are line bored at the factory, which means they HAVE to stay with the part they were milled with at the time the head was originally manufactured. That also means they have to be oriented in the correct direction. Installing them 180 out is possible.
The other possiblity is that they are binding the cam by having been overtorqued when they were reinstalled.
Or *maybe* they woren't oiled before installation, which would have caused a dry start and possible galling.
I was at the library using Alldata this morning and looked up your vehicle.
There is a very complex procedure for setting up tension on the balance shaft chain. It involves fabricating a piece of hardwood as a setting jig for the tension. It is placed in the notch of chain guide "c" to setup proper slack
Buy the manual and follow the directions.
Maybe if you go to a dealership and talk to a service guy they might run off the pages of procedure you need from the factory book as a favor to you.