[Raptor]

It is definately easier to put it with the tranny bolted to the motor, intake, exhaust turbo etc. Less of a PITA in the long run. On the same lines, you really should have the turbo, lines etc bolted up to the longblock before the timing belt is on then you can prime the oiling system with a drill motor and watch the cam followers to make sure the oiling system is functioning correctly with no blocked passages etc. It might seem a bit overkill, but I have found cases where it paid off to watch the followers. If you spend the time to build the motor, you should definately prime it before initial startup. There other ways to prime it, but this is actually pretty simple and it has the parts all have to end up on the motor at some point, just do it in the right order and it works out perfectly.