You have to rotate the exhaust first so the core is upright (oil input at top and outlet as close to vertical as possible) tighten it all up and the do the same with the compressor housing.

Before doing the final tightening, fit the wastegate actuator. This also has to line up to the wastegate control arm.

The plates that you tighten with the bolts have the same effect as a v-band. Once all are untight, the core should rotate freely