I know some of you guys have mixed opinions on certain aspects of the run in process, But I have had a mechanic tell me to drive the engine under light load on/off no constant labouring for 500kms then bring it back for oil change / analysis.
 
I was going to do it for 100kms and then drop the oil, anyone else think 500kms is a bit excessive?...
 
This engine just cost me a bit so I don't want to ruin it!.

500-1000km is fine. I don't agree with the light load only bit though.

Go with what the eng builder says, I would imagine they'd give all their rebuilds the same advice.  However oil is cheap...

That mileage is fine, but agree with MCT, don't agree with the low load thing unless its a rotary.

righto, so give her a few herbs on and off and do the first 500 with that?... but no constant load droning and labouring yeah?...