I thought the "running in" was soemthing the older engines required. I remeber people in their EH holdens and other cars with "running in" signs on the boot to let people know why they're not driving or accelerating fast.
However, I beleive newer engines (1970 onwards) don't need a special run-in period. Being new, you just treat it carefully and don't red line the engine or put it under duress for a few thousand kms.
Then again, I may be mistaken. I'm sure, a long time ago, I scanned the net and found some info on this. Also, I think I've got some running-in info for the 18RG (and the 2TG would be similar) from my mechanic when he rebuilt my engine. I'll see if I can find it around -it should be with all my car logbooks and history stuff.