Please Help

engine overheated. did top overhaul. head completely reconditioned.
tried to start engine but did not start. compression readings around
200kpa. did complete engine overhaul- new pistons and rings, rebore.
working gaps on 0,30 on compression rings. engine did not start.
compression for both wet and dry tests around 400kpa on all cylinders.
rocked number4 to get tdc on 1. marks spot-on
is there any other way of setting the valve timing on FS9 engine?
what could be other possible causes of lack of compression